test(kms): move the Vault KV2 Transit-wrapping doc guard into check_fips_wording.sh

`test_vault_kv2_sources_do_not_claim_transit_wrapping` asserted that four `include_str!`-pinned files never describe the Vault KV2 backend as wrapping key material through Vault's Transit engine. The invariant is a documentation-claim invariant with no behavioral twin by construction, and the test form was weak in both directions: it saw only four files (the same prose in a fifth file passed silently) and it stopped compiling — rather than reporting a violation — as soon as one of them was renamed. Move the four literals verbatim into `scripts/check_fips_wording.sh`, which already guards the adjacent cryptographic over-claim class (unsupported FIPS validation wording) and is anchored to the same policy document. The guard now greps every file under `crates/kms` for the same four case-sensitive literals and separately reports a moved pinned source instead of failing to build. `check_fips_wording.sh` previously ran only in `make pre-commit` / `pre-pr`, so wire it into the Quick Checks job of both CI workflows to keep the invariant's failure visibility at least as strong as the deleted test's.
test(e2e): drop 187 no-op serial markers from the three densest e2e suites (#6209 )
2026-08-18 10:43:15 +00:00 · 2026-08-18 17:30:11 +08:00 · 2026-08-18 17:05:30 +08:00 · 2026-08-18 17:04:55 +08:00 · 2026-08-18 08:14:05 +00:00 · 2026-08-18 16:09:30 +08:00
467 changed files with 55696 additions and 15675 deletions
@@ -66,8 +66,8 @@ s3s-footprint-check: ## Check the s3s dependency footprint ratchet stays frozen
 	./scripts/check_s3s_footprint.sh

 .PHONY: fips-wording-check
-fips-wording-check: ## Check outward docs do not make unsupported FIPS claims
-	@echo "📣 Checking FIPS wording guard..."
+fips-wording-check: ## Check docs and crates/kms do not over-claim crypto capabilities
+	@echo "📣 Checking cryptographic capability wording guard..."
 	./scripts/check_fips_wording.sh

 .PHONY: log-analyzer-rules-check
@@ -252,10 +252,16 @@ test-group = 'ecstore-serial-flaky'
 # cluster, so it keeps the lane's parallel-safe / no-external-dependency
 # properties. The RustFS warm backend has no loopback guard (that guard is
 # replication-only), so it needs no opt-in env for its 127.0.0.1 tier target.
+#
+# Disk compression (backlog#1848): the `compression` module joins the smoke
+# lane so the multipart disk-compression roundtrips (restored after
+# rustfs/rustfs#5169 disabled them) have PR-lane signal, not just merge-gate.
+# Single-node servers on random ports with isolated temp dirs — meets the
+# admission criteria unchanged.
 [profile.e2e-smoke]
 default-filter = """
    package(e2e_test) & (
-        test(/^(delete_marker_migration_semantics|version_id_regression|list_objects_v2_pagination|list_object_versions_regression|list_objects_duplicates|list_buckets_double_slash|list_buckets_auth|list_buckets_iam_filter|leading_slash_key|special_chars|create_bucket_region|delete_objects_versioning|head_object_consistency|head_object_range|copy_object_metadata|copy_object_tagging|copy_source_invalid_date|content_encoding|multipart_storage_class|storage_class_capability|ssec_copy|anonymous_access|bucket_policy_check|presigned_negative|negative_sigv4|admin_auth|notification_webhook|tls_hot_reload|console_smoke|admin_iam_crud|admin_pools|sts_query_compat)_test::|^fake_s3_target::/)
+        test(/^(delete_marker_migration_semantics|version_id_regression|list_objects_v2_pagination|list_object_versions_regression|list_objects_duplicates|list_buckets_double_slash|list_buckets_auth|list_buckets_iam_filter|leading_slash_key|special_chars|create_bucket_region|delete_objects_versioning|head_object_consistency|head_object_range|copy_object_metadata|copy_object_tagging|copy_source_invalid_date|content_encoding|compression|multipart_storage_class|storage_class_capability|ssec_copy|anonymous_access|bucket_policy_check|presigned_negative|negative_sigv4|admin_auth|notification_webhook|tls_hot_reload|console_smoke|admin_iam_crud|admin_pools|sts_query_compat)_test::|^fake_s3_target::/)
        | test(/^replication_extension_test::(test_replication_check_succeeds_with_remote_target|test_replication_check_rejects_target_without_object_lock|test_set_remote_target_rejects_unversioned_source_bucket|test_replication_check_rejects_unversioned_source_bucket|test_replication_check_rejects_missing_replication_config|test_replication_check_rejects_invalid_bucket|test_set_remote_target_rejects_same_bucket_on_same_deployment|test_set_remote_target_rejects_unversioned_target_bucket|test_set_remote_target_update_requires_arn|test_set_remote_target_update_rejects_missing_target|test_set_remote_target_rejects_invalid_target_url|test_set_remote_target_rejects_self_signed_https_target_without_skip_tls_verify|test_set_remote_target_rejects_private_ca_https_target_without_ca_cert_pem|test_list_remote_targets_rejects_empty_bucket|test_list_remote_targets_rejects_invalid_bucket|test_remove_remote_target_rejects_missing_target|test_remove_remote_target_rejects_missing_arn|test_remove_remote_target_rejects_invalid_bucket|test_remove_remote_target_rejects_target_used_by_replication|test_delete_bucket_replication_removes_remote_target)$/)
        | test(/^reliant::lifecycle::/)
        | test(/^reliant::tiering::/)
@@ -182,7 +182,12 @@ jobs:
            echo '```'
          } >> "$GITHUB_STEP_SUMMARY"

-  # Readers: test-and-lint-rio-v2, build-rustfs-debug-binary-rio-v2.
+  # Readers: test-and-lint-rio-v2 (per-PR), build-rustfs-debug-binary-rio-v2
+  # (weekly schedule / manual dispatch only — dormant rio-v2 variant, see
+  # rustfs/backlog#1835 and docs/architecture/minio-file-format-compat.md).
+  # The second build below stays despite the reduced cadence: it warms the
+  # rio-v2,e2e-test-hooks feature resolution the scheduled build restores,
+  # which keeps that lane inside its 30-minute timeout.
  warm-ci-feat-rio:
    name: Warm ci-feat-rio
    runs-on: sm-standard-4
@@ -117,6 +117,9 @@ jobs:
      - name: Check s3s footprint ratchet
        run: ./scripts/check_s3s_footprint.sh

+      - name: Check cryptographic capability wording
+        run: ./scripts/check_fips_wording.sh
+
      - name: Check no planning docs committed
        run: ./scripts/check_no_planning_docs.sh

@@ -152,6 +152,9 @@ jobs:
      - name: Check s3s footprint ratchet
        run: ./scripts/check_s3s_footprint.sh

+      - name: Check cryptographic capability wording
+        run: ./scripts/check_fips_wording.sh
+
      - name: Check no planning docs committed
        run: ./scripts/check_no_planning_docs.sh

@@ -533,7 +536,12 @@ jobs:

  build-rustfs-debug-binary-rio-v2:
    name: Build RustFS Debug Binary (rio-v2)
-    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    # Dormant rio-v2 variant (rustfs/backlog#1835): the feature ships in no
+    # default build, so this full-suite lane runs only on the weekly schedule
+    # and manual dispatch. Per-PR cfg-seam coverage stays with
+    # test-and-lint-rio-v2. Lifecycle and the promote-or-delete condition:
+    # docs/architecture/minio-file-format-compat.md ("rio-v2 variant lifecycle").
+    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 30
@@ -824,6 +832,9 @@ jobs:

  e2e-tests-rio-v2:
    name: End-to-End Tests (rio-v2)
+    # Inherits the schedule/dispatch-only gate through needs: on every other
+    # event build-rustfs-debug-binary-rio-v2 is skipped, so this job skips
+    # with it (see the dormant-variant comment on that job).
    needs: [ build-rustfs-debug-binary-rio-v2 ]
    runs-on: sm-standard-2
    timeout-minutes: 30
@@ -94,6 +94,7 @@ jobs:
      short_sha: ${{ steps.check.outputs.short_sha }}
      is_prerelease: ${{ steps.check.outputs.is_prerelease }}
      create_latest: ${{ steps.check.outputs.create_latest }}
+      source_ref: ${{ steps.check.outputs.source_ref }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
@@ -118,6 +119,7 @@ jobs:
          short_sha=""
          is_prerelease=false
          create_latest=false
+          source_ref="$GITHUB_SHA"

          if [[ "${{ github.event_name }}" == "workflow_run" ]]; then
            # Triggered by build workflow completion
@@ -137,6 +139,7 @@ jobs:
            # Extract version info from commit message or use commit SHA
            # Use Git to generate consistent short SHA (ensures uniqueness like build.yml)
            short_sha=$(git rev-parse --short "$HEAD_SHA")
+            source_ref="$HEAD_SHA"

            # Determine build type based on triggering workflow event and ref
            triggering_event="$TRIGGERING_EVENT"
@@ -261,6 +264,23 @@ jobs:
                echo "⚠️  Only release versions (latest, v1.0.0, 1.0.0) and prereleases (v1.0.0-alpha1, 1.0.0-beta2) are supported"
                ;;
            esac
+
+            if [[ "$should_build" == true && "$input_version" != "latest" ]]; then
+              tag_ref="refs/tags/$input_version"
+              if ! git ls-remote --exit-code origin "$tag_ref" >/dev/null 2>&1; then
+                if [[ "$input_version" == v* ]]; then
+                  tag_ref="refs/tags/${input_version#v}"
+                else
+                  tag_ref="refs/tags/v$input_version"
+                fi
+              fi
+
+              if ! git ls-remote --exit-code origin "$tag_ref" >/dev/null 2>&1; then
+                echo "❌ Release tag not found for Docker build: $input_version"
+                exit 1
+              fi
+              source_ref="$tag_ref"
+            fi
          fi

          {
@@ -271,6 +291,7 @@ jobs:
            echo "short_sha=$short_sha"
            echo "is_prerelease=$is_prerelease"
            echo "create_latest=$create_latest"
+            echo "source_ref=$source_ref"
          } >> "$GITHUB_OUTPUT"

          echo "🐳 Docker Build Summary:"
@@ -281,6 +302,7 @@ jobs:
          echo "  - Short SHA: $short_sha"
          echo "  - Is prerelease: $is_prerelease"
          echo "  - Create latest: $create_latest"
+          echo "  - Source ref: $source_ref"

  # Build multi-arch Docker images
  # Strategy: Build images using pre-built binaries from dl.rustfs.com
@@ -308,6 +330,7 @@ jobs:
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
          persist-credentials: false
+          ref: ${{ needs.build-check.outputs.source_ref }}

      - name: Login to Docker Hub
        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
@@ -397,7 +420,8 @@ jobs:
          LABELS="org.opencontainers.image.title=RustFS"
          LABELS="$LABELS,org.opencontainers.image.description=RustFS distributed object storage system"
          LABELS="$LABELS,org.opencontainers.image.version=$VERSION"
-          LABELS="$LABELS,org.opencontainers.image.revision=${{ github.sha }}"
+          SOURCE_REVISION="$(git rev-parse HEAD)"
+          LABELS="$LABELS,org.opencontainers.image.revision=$SOURCE_REVISION"
          LABELS="$LABELS,org.opencontainers.image.source=${{ github.server_url }}/${{ github.repository }}"
          LABELS="$LABELS,org.opencontainers.image.created=$(date -u +'%Y-%m-%dT%H:%M:%SZ')"
          LABELS="$LABELS,org.opencontainers.image.build-type=$BUILD_TYPE"
@@ -15,28 +15,35 @@
 # Package Workflow - Build DEB/RPM packages
 #
 # This workflow builds DEB and RPM packages from pre-built Linux binaries
-# and uploads them to Cloudflare R2.
+# and uploads them to Cloudflare R2 and the GitHub release.
 #
 # Trigger:
-# - release published: automatically package when a GitHub release is published
-# - workflow_dispatch: manual trigger with optional tag/run_id
+# - workflow_run: automatically package after "Build and Release" completes
+#   for a release tag (the mac/windows/linux binaries are already uploaded
+#   to the GitHub release before packaging starts)
+# - workflow_dispatch: manual fallback (backfill / re-run) with optional tag/run_id
 #
 # Flow:
-# 1. Find the Build workflow run for the release tag
+# 1. Resolve the triggering Build workflow run for the release tag
 # 2. Download Linux binaries (x86_64-gnu, aarch64-gnu) from build artifacts
 # 3. Build DEB packages for amd64 and arm64
 # 4. Build RPM packages for x86_64 and aarch64
-# 5. Upload all packages to Cloudflare R2
+# 5. Upload all packages to Cloudflare R2 and the GitHub release

 name: Package DEB/RPM

 permissions:
-  contents: read
+  # contents: write is required to upload packages to the GitHub release
+  contents: write
  actions: read

 on:
-  release:
-    types: [ published ]
+  # Follows the same pattern as docker.yml: run after the release build
+  # workflow completes, so packaging is triggered only by release tags
+  # (e.g. 1.0.0-rc.2, 1.0.0-rc.3), never by development builds.
+  workflow_run:
+    workflows: [ "Build and Release" ]
+    types: [ completed ]
  workflow_dispatch:
    inputs:
      tag:
@@ -49,13 +56,26 @@ on:
        type: string

 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.release.tag_name || github.event.inputs.tag || github.run_id }}
+  group: ${{ github.workflow }}-${{ github.event.workflow_run.head_branch || github.event.inputs.tag || github.run_id }}
  cancel-in-progress: true

+env:
+  HEAD_BRANCH: ${{ github.event.workflow_run.head_branch }}
+  WORKFLOW_RUN_ID: ${{ github.event.workflow_run.id }}
+
 jobs:
  # Resolve which build run to use and extract version info
  resolve:
    name: Resolve Build
+    # Auto-trigger only from successful tag builds of "Build and Release".
+    # Tag pushes arrive as event == push with head_branch != main (a
+    # non-main push head_branch is the release tag name). Manual dispatch
+    # stays available as a fallback for backfills and re-runs.
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      (github.event.workflow_run.conclusion == 'success' &&
+       github.event.workflow_run.event == 'push' &&
+       github.event.workflow_run.head_branch != 'main')
    runs-on: ubuntu-latest
    timeout-minutes: 10
    outputs:
@@ -75,8 +95,8 @@ jobs:
          set -euo pipefail

          # Determine tag
-          if [[ "${{ github.event_name }}" == "release" ]]; then
-            TAG="${{ github.event.release.tag_name }}"
+          if [[ "${{ github.event_name }}" == "workflow_run" ]]; then
+            TAG="${HEAD_BRANCH}"
          elif [[ -n "$INPUT_TAG" ]]; then
            TAG="$INPUT_TAG"
          else
@@ -93,6 +113,11 @@ jobs:
            BUILD_RUN_ID="$INPUT_RUN_ID"
            echo "Using explicit build run ID: $BUILD_RUN_ID"

+          elif [[ "${{ github.event_name }}" == "workflow_run" ]]; then
+            # Use the Build and Release run that triggered this workflow
+            BUILD_RUN_ID="${WORKFLOW_RUN_ID}"
+            echo "Using triggering workflow run: $BUILD_RUN_ID"
+
          elif [[ -n "$TAG" ]]; then
            # Find the build run that produced this tag
            echo "Looking for build run for tag: $TAG"
@@ -456,6 +481,54 @@ jobs:
            echo "✅ Latest packages updated"
          fi

+      - name: Upload packages to GitHub Release
+        if: needs.resolve.outputs.tag != ''
+        env:
+          GH_TOKEN: ${{ github.token }}
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          TAG="${{ needs.resolve.outputs.tag }}"
+          DEB_FILE="${{ steps.deb.outputs.deb_file }}"
+          RPM_FILE="${{ steps.rpm.outputs.rpm_file }}"
+
+          # Upload the packages, then refresh the release checksums so the new
+          # assets are covered, matching the binary release flow.
+          for f in "$DEB_FILE" "$RPM_FILE"; do
+            if [[ -n "$f" && -f "$f" ]]; then
+              echo "📤 Uploading $(basename "$f") to GitHub release ${TAG}..."
+              gh release upload "$TAG" "$f" --clobber
+            fi
+          done
+
+          CHECKSUM_DIR="$(mktemp -d)"
+          gh release download "$TAG" -p 'SHA256SUMS' -p 'SHA512SUMS' \
+            -D "$CHECKSUM_DIR" --clobber 2>/dev/null || true
+
+          for spec in "SHA256SUMS:sha256sum" "SHA512SUMS:sha512sum"; do
+            asset="${spec%%:*}"
+            checksum_cmd="${spec##*:}"
+            checksum_file="${CHECKSUM_DIR}/${asset}"
+
+            touch "$checksum_file"
+
+            for f in "$DEB_FILE" "$RPM_FILE"; do
+              if [[ -n "$f" && -f "$f" ]]; then
+                base="$(basename "$f")"
+                # Remove any stale entry, then append the fresh digest
+                grep -Fv -- "$base" "$checksum_file" > "${checksum_file}.tmp" || true
+                mv "${checksum_file}.tmp" "$checksum_file"
+                (cd "$(dirname "$f")" && "$checksum_cmd" -- "$base") >> "$checksum_file"
+              fi
+            done
+
+            echo "📤 Updating ${asset} for release ${TAG}..."
+            gh release upload "$TAG" "$checksum_file" --clobber
+          done
+
+          echo "✅ GitHub release assets updated"
+
  # Summary
  summary:
    name: Summary
@@ -31,7 +31,7 @@ HTTP request
      → storage/ecfs (erasure coding, encryption, checksums)
        → ecstore (disk pool selection, data distribution)
          → rio (reader pipeline: encrypt → compress → hash → write)
-            → io-core (zero-copy I/O, buffer pool, direct I/O)
+            → io-core (buffer pool, storage profiling, admission control)
              → local disk / remote disk via RPC
 ```

@@ -55,7 +55,7 @@ rustfs/                      # Workspace root (virtual manifest)
 ├── crates/                  # library crates (authoritative list: Cargo.toml [workspace].members)
 │   ├── ecstore/             # Erasure-coded storage engine
 │   ├── rio/                 # Reader I/O pipeline (encrypt, compress, hash)
-│   ├── io-core/             # Zero-copy I/O, scheduling, buffer pool
+│   ├── io-core/             # Buffer pool, storage profiling, admission control
 │   ├── io-metrics/          # I/O metrics collection
 │   ├── common/              # Shared runtime state, globals, data usage types
 │   ├── config/              # Configuration types and parsing
@@ -101,7 +101,10 @@ refactors.

 The `rustfs` binary crate composes these libraries into the running server.
 `ecstore` remains the storage engine at the architectural center; its internal
-module split is tracked under `docs/architecture/`.
+module split is tracked under `docs/architecture/`. `rio-v2` is the
+feature-gated MinIO on-disk format compatibility I/O layer; it ships in no
+default build (lifecycle:
+[docs/architecture/minio-file-format-compat.md](docs/architecture/minio-file-format-compat.md)).

 ## Architecture Invariants

@@ -299,7 +302,7 @@ The binary (`main.rs`) boots in this order:
              │                  │                  │
        ┌─────▼──────┐    ┌──────▼──────┐    ┌──────▼──────┐
        │  ecstore   │    │     rio     │    │   io-core   │
-        │   (core)   │    │  (readers)  │    │ (zero-copy) │
+        │   (core)   │    │  (readers)  │    │ (buffers)   │
        └─────┬──────┘    └─────────────┘    └─────────────┘
              │
     ┌─────┬──┼──┬─────┬──────┐
@@ -311,7 +314,7 @@ The binary (`main.rs`) boots in this order:

 - **"Where does S3 PutObject go?"**
  `server/` routes → `app/object_usecase` validates → `storage/ecfs` encodes →
-  `ecstore` distributes → `rio` encrypts/compresses → `io-core` writes
+  `ecstore` distributes → `rio` encrypts/compresses → `io-core` supplies buffers

 - **"Where are bucket policies enforced?"**
  `app/bucket_usecase` calls into `crates/policy/`
@@ -41,7 +41,7 @@ members = [
    "crates/protocols", # Protocol implementations (FTPS, SFTP, etc.)
    "crates/protos", # Protocol buffer definitions
    "crates/rio", # Rust I/O utilities and abstractions
-    "crates/rio-v2", # Next-generation Rust I/O compatibility layer
+    "crates/rio-v2", # MinIO on-disk format compatibility I/O layer (feature-gated, ships in no default build)
    "crates/replication", # Replication contracts and wire formats
    "crates/concurrency", # Concurrency management for RustFS - timeout, locking, backpressure, and I/O scheduling
    "crates/s3-types", # S3 event type definitions
@@ -69,7 +69,7 @@ edition = "2024"
 license = "Apache-2.0"
 repository = "https://github.com/rustfs/rustfs"
 rust-version = "1.97.1"
-version = "1.0.0-rc.1"
+version = "1.0.0-rc.2"
 homepage = "https://rustfs.com"
 description = "RustFS is a high-performance distributed object storage software built using Rust, one of the most popular languages worldwide. "
 keywords = ["RustFS", "Minio", "object-storage", "filesystem", "s3"]
@@ -86,52 +86,52 @@ redundant_clone = "warn"

 [workspace.dependencies]
 # RustFS Internal Crates
-rustfs = { path = "./rustfs", version = "1.0.0-rc.1" }
-rustfs-heal = { path = "crates/heal", version = "1.0.0-rc.1" }
-rustfs-audit = { path = "crates/audit", version = "1.0.0-rc.1" }
-rustfs-checksums = { path = "crates/checksums", version = "1.0.0-rc.1" }
-rustfs-common = { path = "crates/common", version = "1.0.0-rc.1" }
-rustfs-data-usage = { path = "crates/data-usage", version = "1.0.0-rc.1" }
-rustfs-config = { path = "./crates/config", version = "1.0.0-rc.1" }
-rustfs-concurrency = { path = "./crates/concurrency", version = "1.0.0-rc.1" }
-rustfs-credentials = { path = "crates/credentials", version = "1.0.0-rc.1" }
-rustfs-crypto = { path = "crates/crypto", version = "1.0.0-rc.1" }
-rustfs-ecstore = { path = "crates/ecstore", version = "1.0.0-rc.1" }
-rustfs-filemeta = { path = "crates/filemeta", version = "1.0.0-rc.1" }
-rustfs-iam = { path = "crates/iam", version = "1.0.0-rc.1" }
-rustfs-keystone = { path = "crates/keystone", version = "1.0.0-rc.1" }
-rustfs-lifecycle = { path = "crates/lifecycle", version = "1.0.0-rc.1" }
-rustfs-kms = { path = "crates/kms", version = "1.0.0-rc.1" }
-rustfs-lock = { path = "crates/lock", version = "1.0.0-rc.1" }
-rustfs-madmin = { path = "crates/madmin", version = "1.0.0-rc.1" }
-rustfs-notify = { path = "crates/notify", version = "1.0.0-rc.1" }
-rustfs-io-metrics = { path = "crates/io-metrics", version = "1.0.0-rc.1" }
-rustfs-io-core = { path = "crates/io-core", version = "1.0.0-rc.1" }
-rustfs-object-capacity = { path = "crates/object-capacity", version = "1.0.0-rc.1" }
-rustfs-object-data-cache = { path = "crates/object-data-cache", version = "1.0.0-rc.1", default-features = false }
-rustfs-log-analyzer = { path = "crates/log-analyzer", version = "1.0.0-rc.1" }
-rustfs-obs = { path = "crates/obs", version = "1.0.0-rc.1" }
-rustfs-policy = { path = "crates/policy", version = "1.0.0-rc.1" }
-rustfs-protos = { path = "crates/protos", version = "1.0.0-rc.1" }
-rustfs-protocols = { path = "crates/protocols", version = "1.0.0-rc.1" }
-rustfs-replication = { path = "crates/replication", version = "1.0.0-rc.1" }
-rustfs-rio = { path = "crates/rio", version = "1.0.0-rc.1" }
-rustfs-rio-v2 = { path = "crates/rio-v2", version = "1.0.0-rc.1" }
-rustfs-s3-types = { path = "crates/s3-types", version = "1.0.0-rc.1" }
-rustfs-s3-ops = { path = "crates/s3-ops", version = "1.0.0-rc.1" }
-rustfs-s3select-api = { path = "crates/s3select-api", version = "1.0.0-rc.1" }
-rustfs-s3select-query = { path = "crates/s3select-query", version = "1.0.0-rc.1" }
-rustfs-scanner = { path = "crates/scanner", version = "1.0.0-rc.1" }
-rustfs-security-governance = { path = "crates/security-governance", version = "1.0.0-rc.1" }
-rustfs-extension-schema = { path = "crates/extension-schema", version = "1.0.0-rc.1" }
-rustfs-signer = { path = "crates/signer", version = "1.0.0-rc.1" }
-rustfs-storage-api = { path = "crates/storage-api", version = "1.0.0-rc.1" }
-rustfs-trusted-proxies = { path = "crates/trusted-proxies", version = "1.0.0-rc.1" }
-rustfs-targets = { path = "crates/targets", version = "1.0.0-rc.1" }
-rustfs-test-utils = { path = "crates/test-utils", version = "1.0.0-rc.1" }
-rustfs-tls-runtime = { path = "crates/tls-runtime", version = "1.0.0-rc.1" }
-rustfs-utils = { path = "crates/utils", version = "1.0.0-rc.1" }
-rustfs-zip = { path = "./crates/zip", version = "1.0.0-rc.1" }
+rustfs = { path = "./rustfs", version = "1.0.0-rc.2" }
+rustfs-heal = { path = "crates/heal", version = "1.0.0-rc.2" }
+rustfs-audit = { path = "crates/audit", version = "1.0.0-rc.2" }
+rustfs-checksums = { path = "crates/checksums", version = "1.0.0-rc.2" }
+rustfs-common = { path = "crates/common", version = "1.0.0-rc.2" }
+rustfs-data-usage = { path = "crates/data-usage", version = "1.0.0-rc.2" }
+rustfs-config = { path = "./crates/config", version = "1.0.0-rc.2" }
+rustfs-concurrency = { path = "./crates/concurrency", version = "1.0.0-rc.2" }
+rustfs-credentials = { path = "crates/credentials", version = "1.0.0-rc.2" }
+rustfs-crypto = { path = "crates/crypto", version = "1.0.0-rc.2" }
+rustfs-ecstore = { path = "crates/ecstore", version = "1.0.0-rc.2" }
+rustfs-filemeta = { path = "crates/filemeta", version = "1.0.0-rc.2" }
+rustfs-iam = { path = "crates/iam", version = "1.0.0-rc.2" }
+rustfs-keystone = { path = "crates/keystone", version = "1.0.0-rc.2" }
+rustfs-lifecycle = { path = "crates/lifecycle", version = "1.0.0-rc.2" }
+rustfs-kms = { path = "crates/kms", version = "1.0.0-rc.2" }
+rustfs-lock = { path = "crates/lock", version = "1.0.0-rc.2" }
+rustfs-madmin = { path = "crates/madmin", version = "1.0.0-rc.2" }
+rustfs-notify = { path = "crates/notify", version = "1.0.0-rc.2" }
+rustfs-io-metrics = { path = "crates/io-metrics", version = "1.0.0-rc.2" }
+rustfs-io-core = { path = "crates/io-core", version = "1.0.0-rc.2" }
+rustfs-object-capacity = { path = "crates/object-capacity", version = "1.0.0-rc.2" }
+rustfs-object-data-cache = { path = "crates/object-data-cache", version = "1.0.0-rc.2", default-features = false }
+rustfs-log-analyzer = { path = "crates/log-analyzer", version = "1.0.0-rc.2" }
+rustfs-obs = { path = "crates/obs", version = "1.0.0-rc.2" }
+rustfs-policy = { path = "crates/policy", version = "1.0.0-rc.2" }
+rustfs-protos = { path = "crates/protos", version = "1.0.0-rc.2" }
+rustfs-protocols = { path = "crates/protocols", version = "1.0.0-rc.2" }
+rustfs-replication = { path = "crates/replication", version = "1.0.0-rc.2" }
+rustfs-rio = { path = "crates/rio", version = "1.0.0-rc.2" }
+rustfs-rio-v2 = { path = "crates/rio-v2", version = "1.0.0-rc.2" }
+rustfs-s3-types = { path = "crates/s3-types", version = "1.0.0-rc.2" }
+rustfs-s3-ops = { path = "crates/s3-ops", version = "1.0.0-rc.2" }
+rustfs-s3select-api = { path = "crates/s3select-api", version = "1.0.0-rc.2" }
+rustfs-s3select-query = { path = "crates/s3select-query", version = "1.0.0-rc.2" }
+rustfs-scanner = { path = "crates/scanner", version = "1.0.0-rc.2" }
+rustfs-security-governance = { path = "crates/security-governance", version = "1.0.0-rc.2" }
+rustfs-extension-schema = { path = "crates/extension-schema", version = "1.0.0-rc.2" }
+rustfs-signer = { path = "crates/signer", version = "1.0.0-rc.2" }
+rustfs-storage-api = { path = "crates/storage-api", version = "1.0.0-rc.2" }
+rustfs-trusted-proxies = { path = "crates/trusted-proxies", version = "1.0.0-rc.2" }
+rustfs-targets = { path = "crates/targets", version = "1.0.0-rc.2" }
+rustfs-test-utils = { path = "crates/test-utils", version = "1.0.0-rc.2" }
+rustfs-tls-runtime = { path = "crates/tls-runtime", version = "1.0.0-rc.2" }
+rustfs-utils = { path = "crates/utils", version = "1.0.0-rc.2" }
+rustfs-zip = { path = "./crates/zip", version = "1.0.0-rc.2" }

 # Async Runtime and Networking
 async-channel = "2.5.0"
@@ -154,7 +154,7 @@ hyper-rustls = { default-features = false, version = "0.27.9" }
 hyper-util = { version = "0.1.20" }
 http = "1.5.0"
 http-body = "1.1.0"
-http-body-util = "0.1.4"
+http-body-util = "0.1.5"
 minlz = "1.2.3"
 reqwest = "0.13.4"
 rustfs-kafka-async = { version = "1.2.0" }
@@ -171,7 +171,7 @@ tower = { version = "0.5.3" }
 tower-http = { version = "0.7.0" }

 # Serialization and Data Formats
-apache-avro = "0.22.0"
+apache-avro = { version = "0.22.0", features = ["snappy", "zstandard"] }
 bytes = { version = "1.12.1" }
 bytesize = "2.7.0"
 byteorder = "1.5.0"
@@ -228,12 +228,12 @@ atoi = "3.1.0"
 atomic_enum = "0.3.0"
 aws-config = { version = "1.10.1" }
 aws-credential-types = { version = "1.3.0" }
-aws-sdk-kms = { default-features = false, version = "1.114.0" }
-aws-sdk-s3 = { default-features = false, version = "1.141.0" }
-aws-sdk-sts = { default-features = false, version = "1.110.0" }
-aws-smithy-http-client = { default-features = false, version = "1.2.0" }
+aws-sdk-kms = { default-features = false, version = "1.115.0" }
+aws-sdk-s3 = { default-features = false, version = "1.142.0" }
+aws-sdk-sts = { default-features = false, version = "1.111.0" }
+aws-smithy-http-client = { default-features = false, version = "1.3.0" }
 aws-smithy-runtime-api = { version = "1.14.0" }
-aws-smithy-types = { version = "1.6.1" }
+aws-smithy-types = { version = "1.6.2" }
 base64 = "0.23.1"
 base64-simd = "0.8.0"
 brotli = "8.0.4"
@@ -284,8 +284,8 @@ rayon = "1.12.0"
 reed-solomon-erasure = { package = "rustfs-erasure-codec", version = "8.0.2" }
 reed-solomon-simd = "3.1.0"
 regex = { version = "1.13.1" }
-rumqttc = { package = "rumqttc-next", version = "0.33.3" }
-redis = { version = "1.5.0" }
+rumqttc = { package = "rumqttc-next", version = "0.34.0" }
+redis = { version = "1.6.0" }
 rustify = { version = "0.7", default-features = false }
 rustix = { version = "1.1.4" }
 rust-embed = { version = "8.12.0" }
@@ -313,7 +313,7 @@ tracing-subscriber = { version = "0.3.23" }
 transform-stream = "0.3.1"
 url = "2.5.8"
 urlencoding = "2.1.3"
-uuid = { version = "1.24.0" }
+uuid = { version = "1.24.1" }
 vaultrs = { version = "0.8.0" }
 tar = "0.4.46"
 walkdir = "2.5.0"
@@ -341,16 +341,16 @@ libunftp = { version = "0.23.0" }
 unftp-core = "0.1.0"
 suppaftp = { version = "10.0.1" }
 rcgen = { version = "0.14.9", default-features = false, features = ["aws_lc_rs", "crypto", "pem"] }
-russh = { version = "0.62.6" }
+russh = { version = "0.62.7" }
 russh-sftp = "2.4.0"

 # WebDAV
 dav-server = "0.11.0"

 # Performance Analysis and Memory Profiling
-mimalloc = { version = "0.1.52", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "ce6338661179c8be22e516b00af7483f151485a7" }
-libmimalloc-sys = { version = "0.1.49", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "ce6338661179c8be22e516b00af7483f151485a7", features = ["extended"] }
-hotpath = { version = "0.23.2", default-features = false }
+mimalloc = { version = "0.1.52", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "6d4c41bb10c6d9da1d1b6f07b38c4cc051667f11" }
+libmimalloc-sys = { version = "0.1.49", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "6d4c41bb10c6d9da1d1b6f07b38c4cc051667f11", features = ["extended"] }
+hotpath = { version = "0.23.3", default-features = false }
 # Snapshot testing for output format regression detection
 insta = { version = "1.48" }

@@ -116,7 +116,7 @@ chown -R 10001:10001 data logs
 docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:latest

 # Using specific version
-docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:1.0.0-rc.1
+docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:1.0.0-rc.2
 ```

 If you use [podman](https://github.com/containers/podman) instead of docker, you can install the RustFS with the below command
@@ -113,7 +113,7 @@ chown -R 10001:10001 data logs
 docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:latest

 # 使用指定版本运行
-docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:1.0.0-rc.1
+docker run -d -p 9000:9000 -p 9001:9001 -v $(pwd)/data:/data -v $(pwd)/logs:/logs rustfs/rustfs:1.0.0-rc.2
 ```

 如果您通过绑定挂载启用 TLS 证书目录，也请用同样方式准备该目录：
@@ -40,6 +40,7 @@ mak = "mak"
 gae = "gae"
 GAE = "GAE"
 thr = "thr"
+mis = "mis"
 # s3-tests original test names (cannot be changed)
 nonexisted = "nonexisted"
 consts = "consts"
@@ -11,7 +11,6 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-#![allow(dead_code)]

 use base64_simd::STANDARD;

@@ -38,7 +38,10 @@ pub const XXHASH_3_HEADER_NAME: &str = "x-amz-checksum-xxhash3";
 pub const XXHASH_64_HEADER_NAME: &str = "x-amz-checksum-xxhash64";
 pub const XXHASH_128_HEADER_NAME: &str = "x-amz-checksum-xxhash128";

-#[allow(dead_code)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 wire name, resolved by header_name() below and asserted by this crate's tests (backlog#1823)"
+)]
 pub(crate) static MD5_HEADER_NAME: &str = "content-md5";

 pub const CHECKSUM_ALGORITHMS_IN_PRIORITY_ORDER: [&str; 5] =
@@ -476,13 +476,19 @@ impl Checksum for Xxhash64 {
    }
 }

-#[allow(dead_code)]
 #[derive(Debug, Default)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 is not a ChecksumAlgorithm variant and has no arm in into_impl: S3 carries it as its own header, separate from the x-amz-checksum-* family. This impl exists so the two paths share the Checksum trait, and is asserted by this crate's tests (backlog#1823)"
+)]
 struct Md5 {
    hasher: md5::Md5,
 }

-#[allow(dead_code)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 is not a ChecksumAlgorithm variant and has no arm in into_impl: S3 carries it as its own header, separate from the x-amz-checksum-* family. This impl exists so the two paths share the Checksum trait, and is asserted by this crate's tests (backlog#1823)"
+)]
 impl Md5 {
    fn update(&mut self, bytes: &[u8]) {
        use md5::Digest;
@@ -42,6 +42,7 @@ chrono = { workspace = true, features = ["serde"] }
 jiff = { workspace = true, features = ["serde"] }
 metrics = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
+smallvec = { workspace = true }
 rmp-serde = { workspace = true }
 s3s = { workspace = true, features = ["minio"] }
 tracing = { workspace = true }
@@ -224,6 +224,13 @@ pub struct HealOpts {
 pub enum HealAdmissionDropReason {
    QueueFull,
    PolicyDropped,
+    /// HS-06: an admin heal start overlaps (same bucket with mutually
+    /// containing prefixes, or the same erasure set) an already running or
+    /// queued task. Only produced when RUSTFS_HEAL_OVERLAP_POLICY=minio_error.
+    AlreadyRunning,
+    /// HS-06: same as [`Self::AlreadyRunning`] but for paths that merely
+    /// contain (or are contained by) the active task's path.
+    OverlappingPaths,
 }

 impl HealAdmissionDropReason {
@@ -231,6 +238,8 @@ impl HealAdmissionDropReason {
        match self {
            Self::QueueFull => "queue_full",
            Self::PolicyDropped => "policy_dropped",
+            Self::AlreadyRunning => "already_running",
+            Self::OverlappingPaths => "overlapping_paths",
        }
    }
 }
@@ -287,6 +296,9 @@ pub enum HealRequestSource {
    Scanner,
    AutoHeal,
    ReadRepair,
+    /// Mission Repair Feed: intents delivered by error paths and replayed
+    /// from the durable MRF journal.
+    Mrf,
 }

 impl HealRequestSource {
@@ -297,6 +309,7 @@ impl HealRequestSource {
            Self::Scanner => "scanner",
            Self::AutoHeal => "auto_heal",
            Self::ReadRepair => "read_repair",
+            Self::Mrf => "mrf",
        }
    }
 }
@@ -313,6 +326,9 @@ pub enum HealChannelCommand {
    Query {
        heal_path: String,
        client_token: String,
+        /// Incremental result cursor (HS-06): only items with a sequence
+        /// greater than this are returned; `None` keeps the full snapshot.
+        since_seq: Option<u64>,
        response_tx: oneshot::Sender<Result<HealChannelResponse, String>>,
    },
    /// Cancel heal task
@@ -518,10 +534,21 @@ async fn receive_heal_channel_response(

 /// Send heal query request
 pub async fn query_heal_status(heal_path: String, client_token: String) -> Result<HealChannelResponse, String> {
+    query_heal_status_since(heal_path, client_token, None).await
+}
+
+/// Incremental heal query (HS-06): pass the client's last seen sequence
+/// number to receive only newer result items.
+pub async fn query_heal_status_since(
+    heal_path: String,
+    client_token: String,
+    since_seq: Option<u64>,
+) -> Result<HealChannelResponse, String> {
    let (response_tx, response_rx) = oneshot::channel();
    send_heal_command(HealChannelCommand::Query {
        heal_path,
        client_token,
+        since_seq,
        response_tx,
    })
    .await?;
@@ -17,8 +17,10 @@ pub mod globals;
 pub mod heal_channel;
 pub mod last_minute;
 pub mod metrics;
+pub mod mrf_channel;
 mod readiness;
 pub mod table_catalog;
+pub mod trace_bus;

 pub use globals::*;
 pub use readiness::{GlobalReadiness, SystemStage};
@@ -0,0 +1,203 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Mission Repair Feed (MRF) intent channel.
+//!
+//! Producers on error paths (read decode failure, scanner metadata
+//! corruption, partial-write recovery) hand a lightweight [`MrfIntent`] to the
+//! heal crate through a global bounded channel. Delivery is strictly
+//! non-blocking: `try_send_mrf_intent` never awaits and drops the intent
+//! (counting it) when the channel is full or uninitialized — losing one heal
+//! hint is always preferred over stalling an IO path. Durable replay of
+//! unconsumed intents is the consumer's job (see `rustfs-heal`
+//! `heal::mrf_queue`), mirroring MinIO's `.heal/mrf/list.bin`.
+
+use std::sync::{
+    Arc, OnceLock,
+    atomic::{AtomicBool, Ordering},
+};
+use tokio::sync::mpsc;
+use uuid::Uuid;
+
+/// Bounded capacity of the global MRF channel. Backpressure is resolved by
+/// dropping (and counting) intents, never by blocking the producer.
+const MRF_CHANNEL_CAPACITY: usize = 8192;
+
+/// Why an intent was produced. Drives the heal priority mapping on the
+/// consumer side (DecodeFailure -> Urgent, MetadataCorruption -> High,
+/// PartialWrite -> Normal).
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum MrfKind {
+    /// Erasure decode failed while serving a read (read path).
+    DecodeFailure,
+    /// Scanner classified object metadata as corrupt.
+    MetadataCorruption,
+    /// A write left the object with fewer committed shards than the set size.
+    PartialWrite,
+}
+
+impl MrfKind {
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            MrfKind::DecodeFailure => "decode-failure",
+            MrfKind::MetadataCorruption => "metadata-corruption",
+            MrfKind::PartialWrite => "partial-write",
+        }
+    }
+}
+
+/// One repair intent. Kept deliberately small so the in-memory queue and the
+/// journal stay bounded; `bucket`/`object` are `Arc<str>` so re-arming an
+/// intent never re-allocates the strings.
+#[derive(Clone, Debug)]
+pub struct MrfIntent {
+    pub bucket: Arc<str>,
+    pub object: Arc<str>,
+    /// Version the intent targets, as raw UUID bytes.
+    pub version_id: Option<[u8; 16]>,
+    pub kind: MrfKind,
+    pub enqueued_at_ms: u64,
+    /// Times this intent has already been offered to the heal manager.
+    /// Dropped by the consumer once it reaches `MRF_MAX_ATTEMPTS`.
+    pub attempts: u8,
+}
+
+/// Consumer-side retry ceiling before an intent is given up on.
+pub const MRF_MAX_ATTEMPTS: u8 = 3;
+
+impl MrfIntent {
+    /// Rough in-memory footprint used by the queue's byte budget.
+    pub fn estimated_bytes(&self) -> usize {
+        // Struct + strings + version bytes; buckets and objects are usually
+        // far below this bound, so rounding up keeps the budget conservative.
+        64 + self.bucket.len() + self.object.len()
+    }
+}
+
+static GLOBAL_MRF_SENDER: OnceLock<mpsc::Sender<MrfIntent>> = OnceLock::new();
+
+/// Delivery kill-switch, set from `RUSTFS_HEAL_MRF_ENABLE`. Producers check
+/// this before touching the channel so the disabled path stays allocation- and
+/// sync-free.
+static MRF_DELIVERY_ENABLED: AtomicBool = AtomicBool::new(true);
+
+/// Override delivery (used at heal-runtime startup from configuration).
+pub fn set_mrf_delivery_enabled(enabled: bool) {
+    MRF_DELIVERY_ENABLED.store(enabled, Ordering::Relaxed);
+}
+
+/// Whether producers currently deliver intents.
+pub fn mrf_delivery_enabled() -> bool {
+    MRF_DELIVERY_ENABLED.load(Ordering::Relaxed)
+}
+
+/// Create the global MRF channel and return the consumer half. Fails if the
+/// channel is already initialized (the heal runtime is a singleton).
+pub fn init_mrf_channel() -> Result<mpsc::Receiver<MrfIntent>, &'static str> {
+    let (sender, receiver) = mpsc::channel(MRF_CHANNEL_CAPACITY);
+    GLOBAL_MRF_SENDER
+        .set(sender)
+        .map_err(|_| "MRF channel sender already initialized")?;
+    Ok(receiver)
+}
+
+/// Best-effort, non-blocking intent delivery from an error path.
+///
+/// Returns `true` when the intent was accepted into the channel. `false`
+/// means the intent was dropped (feature disabled, channel not yet
+/// initialized, or channel full) — callers must not retry or await; the
+/// existing read-repair / scanner heal paths remain the safety net.
+///
+/// This runs on IO error paths, so it stays synchronous and cheap: one
+/// bounded allocation for the two `Arc<str>` handles plus the channel slot.
+pub fn try_send_mrf_intent(kind: MrfKind, bucket: &str, object: &str, version_id: Option<Uuid>) -> bool {
+    if !mrf_delivery_enabled() {
+        return false;
+    }
+    let Some(sender) = GLOBAL_MRF_SENDER.get() else {
+        return false;
+    };
+    let intent = MrfIntent {
+        bucket: Arc::from(bucket),
+        object: Arc::from(object),
+        version_id: version_id.map(|vid| *vid.as_bytes()),
+        kind,
+        enqueued_at_ms: unix_now_ms(),
+        attempts: 0,
+    };
+    sender.try_send(intent).is_ok()
+}
+
+fn unix_now_ms() -> u64 {
+    // Kept trivial: the timestamp is diagnostic metadata only; wall-clock
+    // failure would be a bug rather than something to handle here.
+    std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .map(|d| d.as_millis() as u64)
+        .unwrap_or(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn intents_estimate_is_conservative() {
+        let intent = MrfIntent {
+            bucket: Arc::from("bucket"),
+            object: Arc::from("object"),
+            version_id: Some([0u8; 16]),
+            kind: MrfKind::DecodeFailure,
+            enqueued_at_ms: 0,
+            attempts: 0,
+        };
+        assert!(intent.estimated_bytes() >= intent.bucket.len() + intent.object.len());
+    }
+
+    #[tokio::test]
+    async fn try_send_delivers_and_respects_capacity() {
+        let mut receiver = init_mrf_channel().expect("first initialization should succeed");
+        assert!(init_mrf_channel().is_err(), "double initialization must fail");
+
+        assert!(try_send_mrf_intent(MrfKind::DecodeFailure, "b", "o", Some(Uuid::nil())));
+        let intent = receiver.recv().await.expect("intent should arrive");
+        assert_eq!(intent.kind, MrfKind::DecodeFailure);
+        assert_eq!(intent.bucket.as_ref(), "b");
+
+        // Disable delivery: producers become no-ops.
+        set_mrf_delivery_enabled(false);
+        assert!(!try_send_mrf_intent(MrfKind::PartialWrite, "b", "o", None));
+        set_mrf_delivery_enabled(true);
+
+        // Fill the bounded channel past capacity: excess intents are dropped,
+        // never blocking.
+        let mut accepted = 0;
+        for _ in 0..(MRF_CHANNEL_CAPACITY + 64) {
+            if try_send_mrf_intent(MrfKind::PartialWrite, "b", "o", None) {
+                accepted += 1;
+            }
+        }
+        assert_eq!(accepted, MRF_CHANNEL_CAPACITY);
+    }
+
+    #[test]
+    fn try_send_without_channel_is_false() {
+        // This test may run after the tokio test above in the same process;
+        // the singleton semantics make a clean "uninitialized" case hard, so
+        // assert the flag-off behavior only.
+        set_mrf_delivery_enabled(false);
+        assert!(!try_send_mrf_intent(MrfKind::MetadataCorruption, "b", "o", None));
+        set_mrf_delivery_enabled(true);
+    }
+}
@@ -0,0 +1,333 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use smallvec::SmallVec;
+use std::{
+    sync::{
+        Arc, OnceLock,
+        atomic::{AtomicUsize, Ordering},
+    },
+    time::{Duration, SystemTime},
+};
+use tokio::sync::broadcast;
+
+const DEFAULT_TRACE_BUS_CAPACITY: usize = 1024;
+const TRACE_ATTR_INLINE_CAPACITY: usize = 8;
+
+static GLOBAL_TRACE_BUS: OnceLock<TraceBus> = OnceLock::new();
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TraceKind {
+    Heal,
+    Scanner,
+}
+
+impl TraceKind {
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::Heal => "heal",
+            Self::Scanner => "scanner",
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TraceFunc {
+    HealTask,
+    HealBucket,
+    HealObject,
+    HealCheckAbandonedParts,
+    HealErasureSetPage,
+    ScannerFolder,
+    ScannerIlmAction,
+    ScannerHealCandidate,
+    Dropped,
+}
+
+impl TraceFunc {
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::HealTask => "heal.Task",
+            Self::HealBucket => "heal.Bucket",
+            Self::HealObject => "heal.Object",
+            Self::HealCheckAbandonedParts => "heal.CheckAbandonedParts",
+            Self::HealErasureSetPage => "heal.ErasureSetPage",
+            Self::ScannerFolder => "scanner.Folder",
+            Self::ScannerIlmAction => "scanner.IlmAction",
+            Self::ScannerHealCandidate => "scanner.HealCandidate",
+            Self::Dropped => "trace.Dropped",
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum TraceVal {
+    Bool(bool),
+    U64(u64),
+    I64(i64),
+    Str(Arc<str>),
+}
+
+impl From<bool> for TraceVal {
+    fn from(value: bool) -> Self {
+        Self::Bool(value)
+    }
+}
+
+impl From<u64> for TraceVal {
+    fn from(value: u64) -> Self {
+        Self::U64(value)
+    }
+}
+
+impl From<i64> for TraceVal {
+    fn from(value: i64) -> Self {
+        Self::I64(value)
+    }
+}
+
+impl From<&str> for TraceVal {
+    fn from(value: &str) -> Self {
+        Self::Str(Arc::from(value))
+    }
+}
+
+impl From<String> for TraceVal {
+    fn from(value: String) -> Self {
+        Self::Str(Arc::from(value))
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TraceAttr {
+    pub key: &'static str,
+    pub value: TraceVal,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TraceEvent {
+    pub kind: TraceKind,
+    pub func: TraceFunc,
+    pub time: SystemTime,
+    pub bucket: Option<Arc<str>>,
+    pub object: Option<Arc<str>>,
+    pub duration: Duration,
+    pub bytes: u64,
+    pub attrs: SmallVec<[TraceAttr; TRACE_ATTR_INLINE_CAPACITY]>,
+}
+
+impl TraceEvent {
+    pub fn new(kind: TraceKind, func: TraceFunc) -> Self {
+        Self {
+            kind,
+            func,
+            time: SystemTime::now(),
+            bucket: None,
+            object: None,
+            duration: Duration::ZERO,
+            bytes: 0,
+            attrs: SmallVec::new(),
+        }
+    }
+
+    pub fn with_bucket(mut self, bucket: impl Into<Arc<str>>) -> Self {
+        self.bucket = Some(bucket.into());
+        self
+    }
+
+    pub fn with_object(mut self, object: impl Into<Arc<str>>) -> Self {
+        self.object = Some(object.into());
+        self
+    }
+
+    pub fn with_duration(mut self, duration: Duration) -> Self {
+        self.duration = duration;
+        self
+    }
+
+    pub fn with_bytes(mut self, bytes: u64) -> Self {
+        self.bytes = bytes;
+        self
+    }
+
+    pub fn with_attr(mut self, key: &'static str, value: impl Into<TraceVal>) -> Self {
+        self.attrs.push(TraceAttr {
+            key,
+            value: value.into(),
+        });
+        self
+    }
+}
+
+#[derive(Debug)]
+pub struct TraceBus {
+    sender: broadcast::Sender<Arc<TraceEvent>>,
+    subscriber_count: Arc<AtomicUsize>,
+}
+
+impl TraceBus {
+    pub fn new(capacity: usize) -> Self {
+        let capacity = capacity.max(1);
+        let (sender, _receiver) = broadcast::channel(capacity);
+        Self {
+            sender,
+            subscriber_count: Arc::new(AtomicUsize::new(0)),
+        }
+    }
+
+    pub fn subscriber_count(&self) -> usize {
+        self.subscriber_count.load(Ordering::Acquire)
+    }
+
+    pub fn subscribe(&self) -> TraceSubscription {
+        let receiver = self.sender.subscribe();
+        self.subscriber_count.fetch_add(1, Ordering::AcqRel);
+        TraceSubscription {
+            receiver,
+            subscriber_count: Arc::clone(&self.subscriber_count),
+        }
+    }
+
+    pub fn emit(&self, build: impl FnOnce() -> TraceEvent) -> bool {
+        if self.subscriber_count() == 0 {
+            return false;
+        }
+
+        self.sender.send(Arc::new(build())).is_ok()
+    }
+}
+
+impl Default for TraceBus {
+    fn default() -> Self {
+        Self::new(DEFAULT_TRACE_BUS_CAPACITY)
+    }
+}
+
+#[derive(Debug)]
+pub struct TraceSubscription {
+    receiver: broadcast::Receiver<Arc<TraceEvent>>,
+    subscriber_count: Arc<AtomicUsize>,
+}
+
+impl TraceSubscription {
+    pub async fn recv(&mut self) -> Result<Arc<TraceEvent>, broadcast::error::RecvError> {
+        self.receiver.recv().await
+    }
+
+    pub fn try_recv(&mut self) -> Result<Arc<TraceEvent>, broadcast::error::TryRecvError> {
+        self.receiver.try_recv()
+    }
+}
+
+impl Drop for TraceSubscription {
+    fn drop(&mut self) {
+        self.subscriber_count.fetch_sub(1, Ordering::AcqRel);
+    }
+}
+
+pub fn global_trace_bus() -> &'static TraceBus {
+    GLOBAL_TRACE_BUS.get_or_init(TraceBus::default)
+}
+
+pub fn subscribe_trace_events() -> TraceSubscription {
+    global_trace_bus().subscribe()
+}
+
+pub fn trace_emit(build: impl FnOnce() -> TraceEvent) -> bool {
+    global_trace_bus().emit(build)
+}
+
+pub fn trace_subscriber_count() -> usize {
+    global_trace_bus().subscriber_count()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::atomic::AtomicUsize;
+
+    #[test]
+    fn trace_emit_skips_builder_without_subscribers() {
+        let bus = TraceBus::new(4);
+        let built = AtomicUsize::new(0);
+
+        let sent = bus.emit(|| {
+            built.fetch_add(1, Ordering::Relaxed);
+            TraceEvent::new(TraceKind::Heal, TraceFunc::HealTask)
+        });
+
+        assert!(!sent);
+        assert_eq!(built.load(Ordering::Relaxed), 0);
+    }
+
+    #[tokio::test]
+    async fn trace_subscriber_receives_event() {
+        let bus = TraceBus::new(4);
+        let mut subscription = bus.subscribe();
+
+        assert!(bus.emit(|| {
+            TraceEvent::new(TraceKind::Heal, TraceFunc::HealObject)
+                .with_bucket("bucket")
+                .with_object("object")
+                .with_duration(Duration::from_millis(7))
+                .with_bytes(11)
+                .with_attr("dry", true)
+        }));
+
+        let event = subscription
+            .recv()
+            .await
+            .expect("subscriber should receive emitted trace event");
+
+        assert_eq!(event.kind, TraceKind::Heal);
+        assert_eq!(event.func, TraceFunc::HealObject);
+        assert_eq!(event.bucket.as_deref(), Some("bucket"));
+        assert_eq!(event.object.as_deref(), Some("object"));
+        assert_eq!(event.duration, Duration::from_millis(7));
+        assert_eq!(event.bytes, 11);
+        assert_eq!(
+            event.attrs.as_slice(),
+            &[TraceAttr {
+                key: "dry",
+                value: TraceVal::Bool(true)
+            }]
+        );
+    }
+
+    #[test]
+    fn trace_subscription_drop_decrements_count() {
+        let bus = TraceBus::new(4);
+        let subscription = bus.subscribe();
+
+        assert_eq!(bus.subscriber_count(), 1);
+        drop(subscription);
+        assert_eq!(bus.subscriber_count(), 0);
+    }
+
+    #[tokio::test]
+    async fn lagged_subscriber_drops_events_without_blocking_publishers() {
+        let bus = TraceBus::new(2);
+        let mut subscription = bus.subscribe();
+
+        for index in 0_u64..4 {
+            assert!(bus.emit(|| { TraceEvent::new(TraceKind::Scanner, TraceFunc::ScannerFolder).with_attr("index", index) }));
+        }
+
+        let err = subscription
+            .recv()
+            .await
+            .expect_err("receiver should observe lag instead of blocking publishers");
+        assert!(matches!(err, broadcast::error::RecvError::Lagged(_)));
+    }
+}
@@ -14,9 +14,8 @@

 //! Shared backpressure policy type.
 //!
-//! The runtime backpressure implementation (byte-watermark pipes and
-//! monitors) lives in `rustfs/src/storage/backpressure.rs`; this module only
-//! carries the watermark policy type that implementation shares.
+//! This module only carries the watermark policy; the admission primitive it
+//! projects into lives in `rustfs-io-core`.

 use rustfs_io_core::BackpressureConfig as CoreBackpressureConfig;

@@ -353,6 +353,11 @@ pub const DEFAULT_OBS_TRACES_EXPORT_ENABLED: bool = true;
 /// Environment variable: RUSTFS_OBS_METRICS_EXPORT_ENABLED
 pub const DEFAULT_OBS_METRICS_EXPORT_ENABLED: bool = true;

+/// Default detailed PUT stage metrics enabled
+/// Default value: false
+/// Environment variable: RUSTFS_OBS_PUT_STAGE_METRICS_ENABLED
+pub const DEFAULT_OBS_PUT_STAGE_METRICS_ENABLED: bool = false;
+
 /// Default logs export enabled
 /// It is used to enable or disable exporting logs
 /// Default value: true
@@ -177,3 +177,40 @@ pub const DEFAULT_HEAL_MAINLINE_WRITE_UTILIZATION_HIGH_PERCENT: usize = 80;

 /// Default foreground pressure recheck delay for heal scheduler, in milliseconds.
 pub const DEFAULT_HEAL_MAINLINE_MAX_SLEEP_MS: u64 = 250;
+
+/// Environment variable that toggles the MRF (mission repair feed) intent
+/// pipeline: error paths deliver repair intents to the heal runtime, and
+/// unconsumed intents are replayed from the durable journal after a restart.
+pub const ENV_HEAL_MRF_ENABLE: &str = "RUSTFS_HEAL_MRF_ENABLE";
+
+/// Environment variable for the MRF in-memory queue capacity (intent count).
+pub const ENV_HEAL_MRF_QUEUE_SIZE: &str = "RUSTFS_HEAL_MRF_QUEUE_SIZE";
+
+/// Environment variable for the MRF journal byte budget. The journal is
+/// compacted once its on-disk size crosses this bound.
+pub const ENV_HEAL_MRF_JOURNAL_MAX_BYTES: &str = "RUSTFS_HEAL_MRF_JOURNAL_MAX_BYTES";
+
+/// Environment variable for the MRF journal replay batch size (intents per
+/// replay push round).
+pub const ENV_HEAL_MRF_REPLAY_BATCH: &str = "RUSTFS_HEAL_MRF_REPLAY_BATCH";
+
+/// Default behavior keeps the MRF intent pipeline enabled.
+pub const DEFAULT_HEAL_MRF_ENABLE: bool = true;
+
+/// Default MRF queue capacity (matches MinIO's 100k MRF list ceiling).
+pub const DEFAULT_HEAL_MRF_QUEUE_SIZE: usize = 100_000;
+
+/// Default MRF journal byte budget (8 MiB), mirroring the channel payload cap.
+pub const DEFAULT_HEAL_MRF_JOURNAL_MAX_BYTES: usize = 8 * 1024 * 1024;
+
+/// Default MRF replay batch size.
+pub const DEFAULT_HEAL_MRF_REPLAY_BATCH: usize = 256;
+
+/// Environment variable selecting how admin heal starts behave when the
+/// requested path overlaps an already running or queued heal: `merge`
+/// (default, keep today's dedup/merge semantics) or `minio_error` (return a
+/// typed already-running / overlapping-paths rejection like madmin).
+pub const ENV_HEAL_OVERLAP_POLICY: &str = "RUSTFS_HEAL_OVERLAP_POLICY";
+
+/// Default overlap policy: merge duplicate/overlapping requests.
+pub const DEFAULT_HEAL_OVERLAP_POLICY: &str = "merge";
@@ -137,6 +137,37 @@ pub const DEFAULT_TIER_REMOTE_VERSION_STATE_FLEET_CONFIRMED: bool = false;
 const _: () = assert!(!DEFAULT_TIER_REMOTE_VERSION_STATE_WRITE);
 const _: () = assert!(!DEFAULT_TIER_REMOTE_VERSION_STATE_FLEET_CONFIRMED);

+/// Request the object-transaction fencing contract used by storage-owned
+/// cleanup receipts and lock-window optimizations.
+///
+/// This is fail-closed: enabling the writer without a live fleet proof rejects
+/// the commit rather than silently using a legacy-safe path.
+pub const ENV_OBJECT_TRANSACTION_FENCING_WRITE: &str = "RUSTFS_OBJECT_TRANSACTION_FENCING_WRITE";
+pub const DEFAULT_OBJECT_TRANSACTION_FENCING_WRITE: bool = false;
+
+/// Operator-attested confirmation that every serving node understands the
+/// object transaction fencing contract.
+pub const ENV_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED: &str = "RUSTFS_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED";
+pub const DEFAULT_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED: bool = false;
+
+const _: () = assert!(!DEFAULT_OBJECT_TRANSACTION_FENCING_WRITE);
+const _: () = assert!(!DEFAULT_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED);
+
+/// Request preserving legacy per-part checksum metadata during data movement.
+///
+/// This remains ineffective until
+/// [`ENV_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED`] is also enabled.
+pub const ENV_DATA_MOVEMENT_PART_CHECKSUMS_WRITE: &str = "RUSTFS_DATA_MOVEMENT_PART_CHECKSUMS_WRITE";
+pub const DEFAULT_DATA_MOVEMENT_PART_CHECKSUMS_WRITE: bool = false;
+
+/// Operator-attested confirmation that every serving node understands the
+/// data-movement per-part checksum sidecar.
+pub const ENV_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED: &str = "RUSTFS_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED";
+pub const DEFAULT_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED: bool = false;
+
+const _: () = assert!(!DEFAULT_DATA_MOVEMENT_PART_CHECKSUMS_WRITE);
+const _: () = assert!(!DEFAULT_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED);
+
 // =============================================================================
 // Concurrent Request Fix - Timeout and Backpressure Configuration
 // =============================================================================
@@ -203,6 +234,31 @@ pub const ENV_OBJECT_DISK_WRITE_ABSOLUTE_CAP: &str = "RUSTFS_OBJECT_DISK_WRITE_A
 /// Default absolute per-object erasure write cap in seconds (`0` = disabled).
 pub const DEFAULT_OBJECT_DISK_WRITE_ABSOLUTE_CAP: u64 = 0;

+/// Enable foreground PutObject request admission.
+///
+/// This is an experimental, default-off foreground write backpressure gate for
+/// strict commit tail investigations. When disabled, PUTs follow the legacy
+/// path and only the existing request counters are updated.
+pub const ENV_PUT_FOREGROUND_ADMISSION_ENABLE: &str = "RUSTFS_PUT_FOREGROUND_ADMISSION_ENABLE";
+pub const DEFAULT_PUT_FOREGROUND_ADMISSION_ENABLE: bool = false;
+
+/// Maximum foreground PutObject requests admitted concurrently per process.
+///
+/// The limit is used only when [`ENV_PUT_FOREGROUND_ADMISSION_ENABLE`] is true.
+/// A value of `0` disables the gate even when the enable flag is present, so a
+/// partially configured rollout cannot reject every PUT.
+pub const ENV_PUT_FOREGROUND_ADMISSION_LIMIT: &str = "RUSTFS_PUT_FOREGROUND_ADMISSION_LIMIT";
+pub const DEFAULT_PUT_FOREGROUND_ADMISSION_LIMIT: usize = 0;
+
+/// Time in milliseconds a foreground PutObject waits for an admission permit.
+///
+/// Once this timeout expires the request fails before body ingest/storage
+/// mutation with S3 `SlowDown`/503. `0` means fail fast when the limit is full.
+pub const ENV_PUT_FOREGROUND_ADMISSION_WAIT_TIMEOUT_MS: &str = "RUSTFS_PUT_FOREGROUND_ADMISSION_WAIT_TIMEOUT_MS";
+pub const DEFAULT_PUT_FOREGROUND_ADMISSION_WAIT_TIMEOUT_MS: u64 = 0;
+
+const _: () = assert!(!DEFAULT_PUT_FOREGROUND_ADMISSION_ENABLE);
+
 /// Environment variable for minimum GetObject timeout in seconds.
 ///
 /// When dynamic timeout calculation is enabled, this is the minimum timeout
@@ -649,4 +705,22 @@ mod remote_version_state_tests {
            "RUSTFS_TIER_REMOTE_VERSION_STATE_FLEET_CONFIRMED"
        );
    }
+
+    #[test]
+    fn data_movement_part_checksum_gate_uses_stable_environment_names() {
+        assert_eq!(super::ENV_DATA_MOVEMENT_PART_CHECKSUMS_WRITE, "RUSTFS_DATA_MOVEMENT_PART_CHECKSUMS_WRITE");
+        assert_eq!(
+            super::ENV_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED,
+            "RUSTFS_DATA_MOVEMENT_PART_CHECKSUMS_FLEET_CONFIRMED"
+        );
+    }
+
+    #[test]
+    fn object_transaction_fencing_gate_uses_stable_environment_names() {
+        assert_eq!(super::ENV_OBJECT_TRANSACTION_FENCING_WRITE, "RUSTFS_OBJECT_TRANSACTION_FENCING_WRITE");
+        assert_eq!(
+            super::ENV_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED,
+            "RUSTFS_OBJECT_TRANSACTION_FENCING_FLEET_CONFIRMED"
+        );
+    }
 }
@@ -44,6 +44,10 @@ pub const ENV_OBS_METRICS_EXPORT_ENABLED: &str = "RUSTFS_OBS_METRICS_EXPORT_ENAB
 pub const ENV_OBS_LOGS_EXPORT_ENABLED: &str = "RUSTFS_OBS_LOGS_EXPORT_ENABLED";
 pub const ENV_OBS_PROFILING_EXPORT_ENABLED: &str = "RUSTFS_OBS_PROFILING_EXPORT_ENABLED";

+/// Enables detailed per-stage PUT metrics. Disabled by default because each
+/// PUT records multiple timers and histograms when attribution is active.
+pub const ENV_OBS_PUT_STAGE_METRICS_ENABLED: &str = "RUSTFS_OBS_PUT_STAGE_METRICS_ENABLED";
+
 pub const ENV_OBS_LOGGER_LEVEL: &str = "RUSTFS_OBS_LOGGER_LEVEL";
 pub const ENV_OBS_LOG_STDOUT_ENABLED: &str = "RUSTFS_OBS_LOG_STDOUT_ENABLED";
 pub const ENV_OBS_LOG_DIRECTORY: &str = "RUSTFS_OBS_LOG_DIRECTORY";
@@ -141,6 +145,7 @@ mod tests {
        assert_eq!(ENV_OBS_METRICS_EXPORT_ENABLED, "RUSTFS_OBS_METRICS_EXPORT_ENABLED");
        assert_eq!(ENV_OBS_LOGS_EXPORT_ENABLED, "RUSTFS_OBS_LOGS_EXPORT_ENABLED");
        assert_eq!(ENV_OBS_PROFILING_EXPORT_ENABLED, "RUSTFS_OBS_PROFILING_EXPORT_ENABLED");
+        assert_eq!(ENV_OBS_PUT_STAGE_METRICS_ENABLED, "RUSTFS_OBS_PUT_STAGE_METRICS_ENABLED");
        // Test log cleanup related env keys
        assert_eq!(ENV_OBS_LOG_MAX_TOTAL_SIZE_BYTES, "RUSTFS_OBS_LOG_MAX_TOTAL_SIZE_BYTES");
        assert_eq!(ENV_OBS_LOG_MAX_SINGLE_FILE_SIZE_BYTES, "RUSTFS_OBS_LOG_MAX_SINGLE_FILE_SIZE_BYTES");
@@ -870,6 +870,157 @@ pub struct DataUsageCacheInfo {
    pub snapshot_complete: bool,
 }

+/// Prefix-level usage over a raw entry map — the shared core behind
+/// [`DataUsageCache::prefix_usage`], usable by any cache-shaped reader (the
+/// scanner's writer-side cache has the same map type).
+///
+/// Cache keys are cleaned literal paths (`bucket/pre/fix`), so sub-prefix
+/// names come straight off the child keys — no reverse mapping exists or is
+/// needed. A compacted prefix carries its aggregate but no children, which
+/// the `compacted` flag reports so callers can say why the breakdown is
+/// empty. `truncated` is set when the breakdown exceeded `max_entries` and
+/// was cut (largest first).
+pub fn prefix_usage_in_cache(
+    cache: &HashMap<String, DataUsageEntry>,
+    bucket: &str,
+    prefix: &str,
+    max_entries: usize,
+) -> Option<PrefixUsageQuery> {
+    let prefix = prefix.trim_matches('/');
+    let root = if prefix.is_empty() {
+        bucket.to_string()
+    } else {
+        format!("{bucket}/{prefix}")
+    };
+    let entry = cache.get(&hash_path(&root).key())?.clone();
+
+    let usage = PrefixUsageSummary::from_entry(&flatten_entry(cache, &entry, 0)?);
+
+    let child_prefix = format!("{root}/");
+    let mut sub_prefixes: Vec<PrefixUsageEntry> = entry
+        .children
+        .iter()
+        .filter_map(|child_key| {
+            let child = cache.get(child_key)?;
+            let child_flat = flatten_entry(cache, child, 1)?;
+            // Child keys are literal `bucket/pre/name` paths; a trailing
+            // slash marks a directory object and is display-only here.
+            let name = child_key
+                .strip_prefix(child_prefix.as_str())
+                .unwrap_or(child_key.as_str())
+                .trim_end_matches('/')
+                .to_string();
+            Some(PrefixUsageEntry {
+                prefix: name,
+                usage: PrefixUsageSummary::from_entry(&child_flat),
+            })
+        })
+        .collect();
+    sub_prefixes.sort_by(|left, right| {
+        right
+            .usage
+            .size
+            .cmp(&left.usage.size)
+            .then_with(|| left.prefix.cmp(&right.prefix))
+    });
+    let truncated = sub_prefixes.len() > max_entries;
+    sub_prefixes.truncate(max_entries);
+
+    Some(PrefixUsageQuery {
+        usage,
+        compacted: entry.compacted,
+        truncated,
+        sub_prefixes,
+    })
+}
+
+/// Maximum subtree depth [`flatten_entry`] will walk before declaring the
+/// cache corrupt — the same bound the scanner's checked flatten uses.
+const PREFIX_USAGE_MAX_DEPTH: usize = 1024;
+
+/// Flatten one entry's subtree into an aggregate: the free-function twin of
+/// [`DataUsageCache::flatten`], carrying the scanner checked-flatten
+/// hardening so a corrupt cache (cycles, over-deep trees, overflowing
+/// counters) yields `None` instead of unbounded recursion or wrapped totals.
+fn flatten_entry(cache: &HashMap<String, DataUsageEntry>, root: &DataUsageEntry, depth: usize) -> Option<DataUsageEntry> {
+    if depth > PREFIX_USAGE_MAX_DEPTH {
+        return None;
+    }
+    let mut flattened = DataUsageEntry::default();
+    if !flattened.checked_merge(root) {
+        return None;
+    }
+    flattened.compacted = root.compacted;
+    // The root itself is not pre-seeded: it is merged above, and a corrupt
+    // child edge pointing back at the root's own key is still terminated by
+    // the visited set on first encounter.
+    let mut visited: HashSet<&str> = HashSet::new();
+    let mut pending: Vec<(&String, usize)> = root.children.iter().map(|child| (child, depth + 1)).collect();
+    while let Some((key, child_depth)) = pending.pop() {
+        if child_depth > PREFIX_USAGE_MAX_DEPTH || !visited.insert(key.as_str()) {
+            return None;
+        }
+        let entry = cache.get(key)?;
+        if !flattened.checked_merge(entry) {
+            return None;
+        }
+        pending.extend(entry.children.iter().map(|child| (child, child_depth + 1)));
+    }
+    flattened.children.clear();
+    Some(flattened)
+}
+
+/// Flattened counters of one prefix subtree, as returned by
+/// [`DataUsageCache::prefix_usage`].
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PrefixUsageSummary {
+    pub size: u64,
+    pub objects: u64,
+    pub versions: u64,
+    pub delete_markers: u64,
+}
+
+impl PrefixUsageSummary {
+    fn from_entry(entry: &DataUsageEntry) -> Self {
+        Self {
+            size: entry.size as u64,
+            objects: entry.objects as u64,
+            versions: entry.versions as u64,
+            delete_markers: entry.delete_markers as u64,
+        }
+    }
+
+    /// Add another set's counters into this one (entries are partitioned by
+    /// set, so per-set results sum).
+    pub fn merge(&mut self, other: &Self) {
+        self.size = self.size.saturating_add(other.size);
+        self.objects = self.objects.saturating_add(other.objects);
+        self.versions = self.versions.saturating_add(other.versions);
+        self.delete_markers = self.delete_markers.saturating_add(other.delete_markers);
+    }
+}
+
+/// One first-level sub-prefix row of a [`PrefixUsageQuery`].
+#[derive(Clone, Debug, PartialEq, Eq, serde::Serialize)]
+pub struct PrefixUsageEntry {
+    pub prefix: String,
+    pub usage: PrefixUsageSummary,
+}
+
+/// Result of [`DataUsageCache::prefix_usage`].
+#[derive(Clone, Debug, Default, PartialEq, Eq, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PrefixUsageQuery {
+    pub usage: PrefixUsageSummary,
+    /// The prefix entry was compacted by the scanner: its aggregate is valid
+    /// but no sub-prefix breakdown exists on disk.
+    pub compacted: bool,
+    /// The breakdown had more entries than `max_entries`; the largest remain.
+    pub truncated: bool,
+    pub sub_prefixes: Vec<PrefixUsageEntry>,
+}
+
 /// Read-only projection of a scanner-written `.usage-cache.bin` file.
 ///
 /// The scanner-side `DataUsageCache` (`crates/scanner/src/data_usage_define.rs`)
@@ -997,6 +1148,21 @@ impl DataUsageCache {
        }
    }

+    /// Prefix-level usage for one bucket subtree, plus the one-level
+    /// breakdown below it (rustfs/backlog#1872, MinIO
+    /// `loadPrefixUsageFromBackend` parity and beyond: arbitrary prefixes and
+    /// full counters instead of first-level sizes only).
+    ///
+    /// Cache keys are cleaned literal paths (`bucket/pre/fix`), so sub-prefix
+    /// names come straight off the child keys — no reverse mapping exists or
+    /// is needed. A compacted prefix carries its aggregate but no children,
+    /// which the `compacted` flag reports so callers can say why the
+    /// breakdown is empty. `truncated` is set when the breakdown exceeded
+    /// `max_entries` and was cut (largest first).
+    pub fn prefix_usage(&self, bucket: &str, prefix: &str, max_entries: usize) -> Option<PrefixUsageQuery> {
+        prefix_usage_in_cache(&self.cache, bucket, prefix, max_entries)
+    }
+
    pub fn force_compact(&mut self, limit: usize) {
        if self.cache.len() < limit {
            return;
@@ -1898,6 +2064,126 @@ mod tests {
        );
    }

+    /// Build a cache shaped like `bucket/{a,b/{c,d}},bucket/loose` with
+    /// distinct counters so aggregation is observable.
+    fn prefix_usage_fixture_cache() -> DataUsageCache {
+        let mut cache = DataUsageCache::default();
+        let mut insert = |path: &str, parent: &str, size: usize, objects: usize, versions: usize, delete_markers: usize| {
+            cache.replace(
+                path,
+                parent,
+                DataUsageEntry {
+                    size,
+                    objects,
+                    versions,
+                    delete_markers,
+                    ..Default::default()
+                },
+            );
+        };
+        insert("bucket", "", 0, 0, 0, 0);
+        insert("bucket/a", "bucket", 100, 1, 1, 0);
+        insert("bucket/b", "bucket", 0, 0, 0, 0);
+        insert("bucket/b/c", "bucket/b", 200, 2, 2, 1);
+        insert("bucket/b/d", "bucket/b", 40, 1, 3, 0);
+        insert("bucket/loose", "bucket", 10, 1, 1, 1);
+        cache
+    }
+
+    #[test]
+    fn prefix_usage_aggregates_bucket_root_and_one_level_below() {
+        let cache = prefix_usage_fixture_cache();
+
+        let root = cache
+            .prefix_usage("bucket", "", 100)
+            .expect("root query must find the bucket entry");
+        assert_eq!(root.usage.size, 350, "root aggregate flattens the whole subtree");
+        assert_eq!(root.usage.objects, 5);
+        assert_eq!(root.usage.versions, 7);
+        assert_eq!(root.usage.delete_markers, 2);
+        assert!(!root.compacted);
+        assert!(!root.truncated);
+        // Breakdown is one level: b (240) before a (100) before loose (10),
+        // each flattened to its own subtree total.
+        let names: Vec<(&str, u64)> = root
+            .sub_prefixes
+            .iter()
+            .map(|entry| (entry.prefix.as_str(), entry.usage.size))
+            .collect();
+        assert_eq!(names, vec![("b", 240), ("a", 100), ("loose", 10)]);
+    }
+
+    #[test]
+    fn prefix_usage_drills_into_arbitrary_prefixes() {
+        let cache = prefix_usage_fixture_cache();
+
+        let b = cache.prefix_usage("bucket", "b", 100).expect("nested prefix must resolve");
+        assert_eq!(b.usage.size, 240);
+        assert_eq!(b.usage.versions, 5);
+        let names: Vec<&str> = b.sub_prefixes.iter().map(|entry| entry.prefix.as_str()).collect();
+        assert_eq!(names, vec!["c", "d"]);
+
+        // Prefix slashes are normalized away.
+        let slashed = cache.prefix_usage("bucket", "/b/", 100).expect("slash-insensitive lookup");
+        assert_eq!(slashed.usage.size, 240);
+
+        assert!(cache.prefix_usage("bucket", "absent", 100).is_none(), "unknown prefix must be a miss");
+        assert!(cache.prefix_usage("other", "", 100).is_none(), "unknown bucket must be a miss");
+    }
+
+    #[test]
+    fn prefix_usage_reports_and_respects_truncation() {
+        let cache = prefix_usage_fixture_cache();
+        let capped = cache.prefix_usage("bucket", "", 2).expect("root query");
+        assert!(capped.truncated, "three children capped to two must flag truncation");
+        let names: Vec<&str> = capped.sub_prefixes.iter().map(|entry| entry.prefix.as_str()).collect();
+        assert_eq!(names, vec!["b", "a"], "largest prefixes survive the cut");
+    }
+
+    #[test]
+    fn prefix_usage_marks_compacted_entries() {
+        let mut cache = DataUsageCache::default();
+        cache.replace(
+            "bucket",
+            "",
+            DataUsageEntry {
+                size: 999,
+                objects: 9,
+                compacted: true,
+                ..Default::default()
+            },
+        );
+
+        let compacted = cache.prefix_usage("bucket", "", 100).expect("compacted root resolves");
+        assert!(compacted.compacted, "compaction must be visible to callers");
+        assert_eq!(compacted.usage.size, 999);
+        assert!(compacted.sub_prefixes.is_empty(), "a compacted entry carries no children");
+    }
+
+    #[test]
+    fn prefix_usage_rejects_cyclic_and_dangling_caches() {
+        // A self-referencing child (corrupt cache) must yield a miss for the
+        // whole query, not unbounded recursion.
+        let mut cache = prefix_usage_fixture_cache();
+        if let Some(entry) = cache.cache.get_mut("bucket/b") {
+            entry.children.insert("bucket/b".to_string());
+        }
+        assert!(cache.prefix_usage("bucket", "b", 100).is_none(), "a cyclic subtree must be rejected");
+        // The unaffected sibling still answers.
+        assert!(cache.prefix_usage("bucket", "a", 100).is_some());
+
+        // A child key with no entry (dangling link) is rejected rather than
+        // silently dropped: half a tree would under-report usage.
+        let mut dangling = prefix_usage_fixture_cache();
+        if let Some(entry) = dangling.cache.get_mut("bucket/b") {
+            entry.children.insert("bucket/b/ghost".to_string());
+        }
+        assert!(
+            dangling.prefix_usage("bucket", "b", 100).is_none(),
+            "a dangling child link must be rejected"
+        );
+    }
+
    #[test]
    fn hash_path_uses_portable_slash_semantics() {
        for (input, expected) in [
@@ -32,6 +32,7 @@ use rustfs_signer::sign_v4;
 use s3s::Body;
 use std::ffi::OsStr;
 use std::fs as stdfs;
+use std::io::ErrorKind;
 use std::path::{Path, PathBuf};
 use std::process::{Child, Command, Stdio};
 use std::sync::Once;
@@ -51,6 +52,11 @@ pub(crate) const FAST_DATA_USAGE_SCANNER_ENV: &[(&str, &str)] =
    &[("RUSTFS_SCANNER_CYCLE", "1"), ("RUSTFS_SCANNER_START_DELAY_SECS", "0")];
 pub const TEST_BUCKET: &str = "e2e-test-bucket";
 const RUSTFS_FULL_FEATURE: &str = "full";
+const TEST_PORT_MIN: u16 = 20_000;
+const TEST_PORT_RANGE: u16 = 40_000;
+const TEST_PORT_COUNTER_PATH: &str = "/tmp/rustfs_e2e_next_port";
+const TEST_PORT_LOCK_DIR: &str = "/tmp/rustfs_e2e_port_allocator.lock";
+const TEST_PORT_LOCK_STALE_AFTER: Duration = Duration::from_secs(30);

 fn capture_log_path(log_dir: &Path, temp_dir: &str) -> Option<PathBuf> {
    let temp_name = Path::new(temp_dir).file_name()?.to_string_lossy();
@@ -67,7 +73,68 @@ fn configured_capture_log_path(temp_dir: &str) -> Option<String> {
    capture_log_path(Path::new(&log_dir), temp_dir).map(|path| path.to_string_lossy().into_owned())
 }

-fn capture_command_logs(command: &mut Command, log_path: Option<&str>) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+struct PortAllocatorGuard;
+
+impl PortAllocatorGuard {
+    async fn acquire() -> Result<Self, Box<dyn std::error::Error + Send + Sync>> {
+        loop {
+            match stdfs::create_dir(TEST_PORT_LOCK_DIR) {
+                Ok(()) => return Ok(Self),
+                Err(err) if err.kind() == ErrorKind::AlreadyExists => {
+                    remove_stale_port_allocator_lock();
+                    sleep(Duration::from_millis(10)).await;
+                }
+                Err(err) => return Err(err.into()),
+            }
+        }
+    }
+}
+
+impl Drop for PortAllocatorGuard {
+    fn drop(&mut self) {
+        let _ = stdfs::remove_dir(TEST_PORT_LOCK_DIR);
+    }
+}
+
+fn advance_test_port(port: u16) -> u16 {
+    let offset = (port - TEST_PORT_MIN + 1) % TEST_PORT_RANGE;
+    TEST_PORT_MIN + offset
+}
+
+fn seeded_test_port() -> u16 {
+    let offset = (Uuid::new_v4().as_u128() % u128::from(TEST_PORT_RANGE)) as u16;
+    TEST_PORT_MIN + offset
+}
+
+fn read_next_test_port() -> u16 {
+    stdfs::read_to_string(TEST_PORT_COUNTER_PATH)
+        .ok()
+        .and_then(|value| value.trim().parse::<u16>().ok())
+        .filter(|port| (TEST_PORT_MIN..TEST_PORT_MIN + TEST_PORT_RANGE).contains(port))
+        .unwrap_or_else(seeded_test_port)
+}
+
+fn remove_stale_port_allocator_lock() {
+    let Ok(metadata) = stdfs::metadata(TEST_PORT_LOCK_DIR) else {
+        return;
+    };
+    let Ok(modified) = metadata.modified() else {
+        return;
+    };
+    if modified.elapsed().is_ok_and(|elapsed| elapsed > TEST_PORT_LOCK_STALE_AFTER) {
+        let _ = stdfs::remove_dir(TEST_PORT_LOCK_DIR);
+    }
+}
+
+fn write_next_test_port(port: u16) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    stdfs::write(TEST_PORT_COUNTER_PATH, port.to_string())?;
+    Ok(())
+}
+
+pub(crate) fn capture_command_logs(
+    command: &mut Command,
+    log_path: Option<&str>,
+) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let Some(log_path) = log_path else {
        return Ok(());
    };
@@ -505,10 +572,21 @@ impl RustFSTestEnvironment {
    /// Find an available port for the test
    pub async fn find_available_port() -> Result<u16, Box<dyn std::error::Error + Send + Sync>> {
        use std::net::TcpListener;
-        let listener = TcpListener::bind("127.0.0.1:0")?;
-        let port = listener.local_addr()?.port();
-        drop(listener);
-        Ok(port)
+        let _guard = PortAllocatorGuard::acquire().await?;
+        let mut next_port = read_next_test_port();
+
+        for _ in 0..TEST_PORT_RANGE {
+            let port = next_port;
+            next_port = advance_test_port(next_port);
+            write_next_test_port(next_port)?;
+
+            if let Ok(listener) = TcpListener::bind(("127.0.0.1", port)) {
+                drop(listener);
+                return Ok(port);
+            }
+        }
+
+        Err("no available E2E test port found".into())
    }

    /// Kill any existing RustFS processes
@@ -2,6 +2,7 @@

 use crate::common::{RustFSTestEnvironment, init_logging, rustfs_binary_path};
 use aws_sdk_s3::primitives::ByteStream;
+use aws_sdk_s3::types::{CompletedMultipartUpload, CompletedPart};
 use serial_test::serial;
 use std::fs;
 use std::path::PathBuf;
@@ -25,6 +26,15 @@ fn generate_compressible_data(size: usize) -> Vec<u8> {
    data
 }

+/// Deterministic 2048-byte-period binary pattern that compresses extremely well: every part
+/// yields many compressed blocks, which is exactly the shape that reproduced the mid-payload
+/// Pending truncation (rustfs/rustfs#5957).
+fn generate_high_ratio_binary_data(size: usize, seed: u8) -> Vec<u8> {
+    (0..size)
+        .map(|i| ((i as u64).wrapping_mul(2_654_435_761).wrapping_add(seed as u64) >> 3) as u8)
+        .collect()
+}
+
 fn find_part_files(temp_dir: &str, bucket: &str, object_key: &str) -> Vec<PathBuf> {
    let bucket_path = PathBuf::from(temp_dir).join(bucket);
    let mut part_files = Vec::new();
@@ -55,9 +65,14 @@ async fn start_rustfs_with_compression(env: &mut RustFSTestEnvironment) -> Resul
    env.cleanup_existing_processes().await?;

    let binary_path = rustfs_binary_path();
-    let process = Command::new(&binary_path)
+    // Route the child's stdout/stderr through the shared RUSTFS_E2E_LOG_DIR
+    // capture (survives the temp-dir cleanup on Drop and is uploaded as a CI
+    // artifact); without the env var the child inherits stdio as before.
+    let mut command = Command::new(&binary_path);
+    command
        .env("RUSTFS_CONSOLE_ENABLE", "false")
        .env("RUSTFS_COMPRESSION_ENABLED", "true")
+        .env("RUSTFS_COMPRESSION_MULTIPART_ENABLED", "true")
        .args([
            "--address",
            &env.address,
@@ -66,8 +81,9 @@ async fn start_rustfs_with_compression(env: &mut RustFSTestEnvironment) -> Resul
            "--secret-key",
            &env.secret_key,
            &env.temp_dir,
-        ])
-        .spawn()?;
+        ]);
+    crate::common::capture_command_logs(&mut command, env.capture_log_path.as_deref())?;
+    let process = command.spawn()?;

    env.process = Some(process);

@@ -154,3 +170,647 @@ async fn test_compression_roundtrip() -> Result<(), Box<dyn std::error::Error +
    env.stop_server();
    Ok(())
 }
+
+const MULTIPART_COMPRESSION_BUCKET: &str = "compression-multipart-bucket";
+const MPU_PART1_SIZE: usize = 5 * 1024 * 1024;
+const MPU_PART2_SIZE: usize = 1024 * 1024;
+
+async fn multipart_upload(
+    client: &aws_sdk_s3::Client,
+    bucket: &str,
+    key: &str,
+    parts: &[&[u8]],
+) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    let create = client.create_multipart_upload().bucket(bucket).key(key).send().await?;
+    let upload_id = create.upload_id().ok_or("missing upload id")?.to_string();
+
+    let mut completed_parts = Vec::with_capacity(parts.len());
+    for (i, part) in parts.iter().enumerate() {
+        let part_number = (i + 1) as i32;
+        let upload = client
+            .upload_part()
+            .bucket(bucket)
+            .key(key)
+            .upload_id(&upload_id)
+            .part_number(part_number)
+            .body(ByteStream::from(part.to_vec()))
+            .send()
+            .await?;
+        completed_parts.push(
+            CompletedPart::builder()
+                .part_number(part_number)
+                .e_tag(upload.e_tag().unwrap_or_default())
+                .build(),
+        );
+    }
+
+    client
+        .complete_multipart_upload()
+        .bucket(bucket)
+        .key(key)
+        .upload_id(&upload_id)
+        .multipart_upload(CompletedMultipartUpload::builder().set_parts(Some(completed_parts)).build())
+        .send()
+        .await?;
+    Ok(())
+}
+
+async fn fetch_range(
+    client: &aws_sdk_s3::Client,
+    bucket: &str,
+    key: &str,
+    range: &str,
+) -> Result<Vec<u8>, Box<dyn std::error::Error + Send + Sync>> {
+    let response = client.get_object().bucket(bucket).key(key).range(range).send().await?;
+    Ok(response.body.collect().await?.into_bytes().to_vec())
+}
+
+/// Multipart disk compression roundtrip: parts are written as independent
+/// compressed streams and every GET shape must reassemble the original bytes
+/// (rustfs/rustfs#5957: multipart uploads previously bypassed disk compression
+/// entirely).
+#[tokio::test]
+#[serial]
+async fn test_compression_multipart_roundtrip() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    init_logging();
+    info!("Starting multipart compression roundtrip test");
+
+    let mut env = RustFSTestEnvironment::new().await?;
+    start_rustfs_with_compression(&mut env).await?;
+
+    let client = env.create_s3_client();
+    env.create_test_bucket(MULTIPART_COMPRESSION_BUCKET).await?;
+
+    let object_key = "multipart-compressible.txt";
+    let part1 = generate_compressible_data(MPU_PART1_SIZE);
+    let part2 = generate_compressible_data(MPU_PART2_SIZE);
+    let mut original_data = part1.clone();
+    original_data.extend_from_slice(&part2);
+    let total_size = original_data.len();
+
+    multipart_upload(&client, MULTIPART_COMPRESSION_BUCKET, object_key, &[&part1, &part2]).await?;
+
+    let head_response = client
+        .head_object()
+        .bucket(MULTIPART_COMPRESSION_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    assert_eq!(
+        head_response.content_length().unwrap_or(0) as usize,
+        total_size,
+        "Content-Length should be the logical object size"
+    );
+
+    let part_files = find_part_files(&env.temp_dir, MULTIPART_COMPRESSION_BUCKET, object_key);
+    assert!(!part_files.is_empty(), "expected on-disk part files for the multipart object");
+    let total_physical_size: u64 = part_files.iter().filter_map(|p| fs::metadata(p).ok()).map(|m| m.len()).sum();
+    assert!(
+        total_physical_size < (total_size / 2) as u64,
+        "Physical size {total_physical_size} should be well below original size {total_size} (multipart compression applied)"
+    );
+    info!("Multipart physical storage size: {total_physical_size} bytes (compressed from {total_size} bytes)");
+
+    // Full GET must reassemble both independently compressed parts.
+    let get_response = client
+        .get_object()
+        .bucket(MULTIPART_COMPRESSION_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    let downloaded = get_response.body.collect().await?.into_bytes();
+    assert_eq!(downloaded.len(), total_size);
+    assert_eq!(&downloaded[..], &original_data[..], "full GET data mismatch");
+
+    // Range fully inside part 1.
+    let range_inside_part1 = fetch_range(&client, MULTIPART_COMPRESSION_BUCKET, object_key, "bytes=1024-999423").await?;
+    assert_eq!(&range_inside_part1[..], &original_data[1024..999424], "part-1 range mismatch");
+
+    // Range crossing the part boundary.
+    let boundary_start = MPU_PART1_SIZE - 128 * 1024;
+    let boundary_end = MPU_PART1_SIZE + 128 * 1024 - 1;
+    let range_crossing = fetch_range(
+        &client,
+        MULTIPART_COMPRESSION_BUCKET,
+        object_key,
+        &format!("bytes={boundary_start}-{boundary_end}"),
+    )
+    .await?;
+    assert_eq!(
+        &range_crossing[..],
+        &original_data[boundary_start..boundary_end + 1],
+        "boundary-crossing range mismatch"
+    );
+
+    // Range fully inside part 2.
+    let part2_start = MPU_PART1_SIZE + 4096;
+    let part2_end = MPU_PART1_SIZE + 256 * 1024 - 1;
+    let range_inside_part2 = fetch_range(
+        &client,
+        MULTIPART_COMPRESSION_BUCKET,
+        object_key,
+        &format!("bytes={part2_start}-{part2_end}"),
+    )
+    .await?;
+    assert_eq!(
+        &range_inside_part2[..],
+        &original_data[part2_start..part2_end + 1],
+        "part-2 range mismatch"
+    );
+
+    // Suffix range (last 128 KiB, entirely in part 2).
+    let suffix_len = 128 * 1024;
+    let suffix = fetch_range(&client, MULTIPART_COMPRESSION_BUCKET, object_key, &format!("bytes=-{suffix_len}")).await?;
+    assert_eq!(&suffix[..], &original_data[total_size - suffix_len..], "suffix range mismatch");
+
+    // partNumber GETs must return each original part.
+    for (part_number, expected) in [(1, &part1), (2, &part2)] {
+        let response = client
+            .get_object()
+            .bucket(MULTIPART_COMPRESSION_BUCKET)
+            .key(object_key)
+            .part_number(part_number)
+            .send()
+            .await?;
+        let body = response.body.collect().await?.into_bytes();
+        assert_eq!(&body[..], &expected[..], "partNumber={part_number} GET mismatch");
+    }
+
+    info!("Multipart compression roundtrip test passed");
+    env.delete_test_bucket(MULTIPART_COMPRESSION_BUCKET).await?;
+    env.stop_server();
+    Ok(())
+}
+
+const MPU_HIGH_RATIO_BUCKET: &str = "compression-mpu-high-ratio-bucket";
+
+/// High-ratio binary multipart payload: the object key is on the compression allow-list, so the
+/// disk-compression path runs and each part is stored as many compressed blocks — the shape that
+/// reproduced the mid-payload Pending truncation (rustfs/rustfs#5957). Every GET shape must return
+/// the exact original bytes, and the stored size must show the data really was compressed.
+#[tokio::test]
+#[serial]
+async fn test_compression_multipart_high_ratio_binary_roundtrip() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    init_logging();
+    info!("Starting multipart high-ratio binary compression roundtrip test");
+
+    let mut env = RustFSTestEnvironment::new().await?;
+    start_rustfs_with_compression(&mut env).await?;
+
+    let client = env.create_s3_client();
+    env.create_test_bucket(MPU_HIGH_RATIO_BUCKET).await?;
+
+    let object_key = "multipart-high-ratio.txt";
+    let part1 = generate_high_ratio_binary_data(MPU_PART1_SIZE, 7);
+    let part2 = generate_high_ratio_binary_data(MPU_PART2_SIZE, 61);
+    let mut original_data = part1.clone();
+    original_data.extend_from_slice(&part2);
+    let total_size = original_data.len();
+
+    multipart_upload(&client, MPU_HIGH_RATIO_BUCKET, object_key, &[&part1, &part2]).await?;
+
+    let head_response = client
+        .head_object()
+        .bucket(MPU_HIGH_RATIO_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    assert_eq!(
+        head_response.content_length().unwrap_or(0) as usize,
+        total_size,
+        "Content-Length should be the logical object size"
+    );
+
+    // This pattern compresses to roughly 1/50 of its logical size, so a comfortably loose 2x
+    // margin still proves the parts were stored compressed rather than raw or double-encoded.
+    let part_files = find_part_files(&env.temp_dir, MPU_HIGH_RATIO_BUCKET, object_key);
+    assert!(!part_files.is_empty(), "expected on-disk part files for the multipart object");
+    let total_physical_size: u64 = part_files.iter().filter_map(|p| fs::metadata(p).ok()).map(|m| m.len()).sum();
+    assert!(
+        total_physical_size < (total_size as u64) / 2,
+        "Physical size {total_physical_size} should be far below the logical size {total_size} for high-ratio data"
+    );
+    info!("High-ratio multipart physical storage size: {total_physical_size} bytes (logical {total_size} bytes)");
+
+    info!("step: full GET");
+    let get_response = client
+        .get_object()
+        .bucket(MPU_HIGH_RATIO_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    let downloaded = get_response.body.collect().await?.into_bytes();
+    assert_eq!(downloaded.len(), total_size);
+    assert_eq!(&downloaded[..], &original_data[..], "full GET data mismatch");
+
+    // Range crossing the part boundary.
+    info!("step: boundary range GET");
+    let boundary_start = MPU_PART1_SIZE - 128 * 1024;
+    let boundary_end = MPU_PART1_SIZE + 128 * 1024 - 1;
+    let range_crossing = fetch_range(
+        &client,
+        MPU_HIGH_RATIO_BUCKET,
+        object_key,
+        &format!("bytes={boundary_start}-{boundary_end}"),
+    )
+    .await?;
+    assert_eq!(
+        &range_crossing[..],
+        &original_data[boundary_start..boundary_end + 1],
+        "boundary-crossing range mismatch"
+    );
+
+    // partNumber GET for the trailing part.
+    info!("step: partNumber GET");
+    let part2_response = client
+        .get_object()
+        .bucket(MPU_HIGH_RATIO_BUCKET)
+        .key(object_key)
+        .part_number(2)
+        .send()
+        .await?;
+    let part2_body = part2_response.body.collect().await?.into_bytes();
+    assert_eq!(&part2_body[..], &part2[..], "partNumber=2 GET mismatch");
+
+    info!("Multipart high-ratio binary compression roundtrip test passed");
+    env.delete_test_bucket(MPU_HIGH_RATIO_BUCKET).await?;
+    env.stop_server();
+    Ok(())
+}
+
+const MPU_COPY_COMPRESSION_BUCKET: &str = "compression-mpu-copy-bucket";
+const MPU_COPY_SOURCE_SIZE: usize = 6 * 1024 * 1024;
+const MPU_COPY_RANGE_LEN: usize = 5 * 1024 * 1024;
+
+/// UploadPartCopy feeds a part from an already stored (and already compressed) object. The copied
+/// range must be decompressed on read and re-compressed into the destination part, so the final
+/// object has to match "source prefix + uploaded tail" byte for byte.
+#[tokio::test]
+#[serial]
+async fn test_compression_multipart_upload_part_copy_roundtrip() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    init_logging();
+    info!("Starting multipart upload-part-copy compression roundtrip test");
+
+    let mut env = RustFSTestEnvironment::new().await?;
+    start_rustfs_with_compression(&mut env).await?;
+
+    let client = env.create_s3_client();
+    env.create_test_bucket(MPU_COPY_COMPRESSION_BUCKET).await?;
+
+    // Source object: a plain PUT that goes through the single-stream compression path.
+    let source_key = "copy-source.txt";
+    let source_data = generate_compressible_data(MPU_COPY_SOURCE_SIZE);
+    client
+        .put_object()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(source_key)
+        .body(ByteStream::from(source_data.clone()))
+        .send()
+        .await?;
+
+    // Destination object: part 1 copied from the source, part 2 uploaded directly.
+    let target_key = "copy-target.txt";
+    let part2 = generate_compressible_data(MPU_PART2_SIZE);
+    let mut expected_data = source_data[..MPU_COPY_RANGE_LEN].to_vec();
+    expected_data.extend_from_slice(&part2);
+    let total_size = expected_data.len();
+
+    let create = client
+        .create_multipart_upload()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .send()
+        .await?;
+    let upload_id = create.upload_id().ok_or("missing upload id")?.to_string();
+
+    let copy_part = client
+        .upload_part_copy()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .upload_id(&upload_id)
+        .part_number(1)
+        .copy_source(format!("{MPU_COPY_COMPRESSION_BUCKET}/{source_key}"))
+        .copy_source_range(format!("bytes=0-{}", MPU_COPY_RANGE_LEN - 1))
+        .send()
+        .await?;
+    let copy_etag = copy_part
+        .copy_part_result()
+        .and_then(|r| r.e_tag())
+        .ok_or("missing copy part etag")?
+        .to_string();
+
+    let uploaded_part = client
+        .upload_part()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .upload_id(&upload_id)
+        .part_number(2)
+        .body(ByteStream::from(part2.clone()))
+        .send()
+        .await?;
+
+    client
+        .complete_multipart_upload()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .upload_id(&upload_id)
+        .multipart_upload(
+            CompletedMultipartUpload::builder()
+                .parts(CompletedPart::builder().part_number(1).e_tag(copy_etag).build())
+                .parts(
+                    CompletedPart::builder()
+                        .part_number(2)
+                        .e_tag(uploaded_part.e_tag().unwrap_or_default())
+                        .build(),
+                )
+                .build(),
+        )
+        .send()
+        .await?;
+
+    let head_response = client
+        .head_object()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .send()
+        .await?;
+    assert_eq!(
+        head_response.content_length().unwrap_or(0) as usize,
+        total_size,
+        "Content-Length should be the logical object size"
+    );
+
+    let part_files = find_part_files(&env.temp_dir, MPU_COPY_COMPRESSION_BUCKET, target_key);
+    assert!(!part_files.is_empty(), "expected on-disk part files for the copied object");
+    let total_physical_size: u64 = part_files.iter().filter_map(|p| fs::metadata(p).ok()).map(|m| m.len()).sum();
+    assert!(
+        total_physical_size < (total_size / 2) as u64,
+        "Physical size {total_physical_size} should be well below original size {total_size} (copied part compression applied)"
+    );
+
+    let get_response = client
+        .get_object()
+        .bucket(MPU_COPY_COMPRESSION_BUCKET)
+        .key(target_key)
+        .send()
+        .await?;
+    let downloaded = get_response.body.collect().await?.into_bytes();
+    assert_eq!(downloaded.len(), total_size);
+    assert_eq!(&downloaded[..], &expected_data[..], "copied multipart GET data mismatch");
+
+    info!("Multipart upload-part-copy compression roundtrip test passed");
+    env.delete_test_bucket(MPU_COPY_COMPRESSION_BUCKET).await?;
+    env.stop_server();
+    Ok(())
+}
+
+const MPU_THREE_PARTS_BUCKET: &str = "compression-mpu-three-parts-bucket";
+const MPU_THREE_PARTS_TAIL_SIZE: usize = 512 * 1024;
+
+/// Three-part upload with uneven part sizes: each partNumber GET must map back to exactly one
+/// compressed part stream, and a suffix range must resolve inside the trailing part.
+#[tokio::test]
+#[serial]
+async fn test_compression_multipart_three_parts_part_number_gets() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    init_logging();
+    info!("Starting three-part multipart compression partNumber test");
+
+    let mut env = RustFSTestEnvironment::new().await?;
+    start_rustfs_with_compression(&mut env).await?;
+
+    let client = env.create_s3_client();
+    env.create_test_bucket(MPU_THREE_PARTS_BUCKET).await?;
+
+    let object_key = "multipart-three-parts.txt";
+    let part1 = generate_compressible_data(MPU_PART1_SIZE);
+    let part2 = generate_compressible_data(MPU_PART1_SIZE);
+    let part3 = generate_compressible_data(MPU_THREE_PARTS_TAIL_SIZE);
+    let mut original_data = part1.clone();
+    original_data.extend_from_slice(&part2);
+    original_data.extend_from_slice(&part3);
+    let total_size = original_data.len();
+
+    multipart_upload(&client, MPU_THREE_PARTS_BUCKET, object_key, &[&part1, &part2, &part3]).await?;
+
+    let head_response = client
+        .head_object()
+        .bucket(MPU_THREE_PARTS_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    assert_eq!(
+        head_response.content_length().unwrap_or(0) as usize,
+        total_size,
+        "Content-Length should be the logical object size"
+    );
+
+    let part_files = find_part_files(&env.temp_dir, MPU_THREE_PARTS_BUCKET, object_key);
+    assert!(!part_files.is_empty(), "expected on-disk part files for the multipart object");
+    let total_physical_size: u64 = part_files.iter().filter_map(|p| fs::metadata(p).ok()).map(|m| m.len()).sum();
+    assert!(
+        total_physical_size < (total_size / 2) as u64,
+        "Physical size {total_physical_size} should be well below original size {total_size} (multipart compression applied)"
+    );
+
+    // Every partNumber GET must return exactly the bytes of the corresponding uploaded part.
+    for (part_number, expected) in [(1, &part1), (2, &part2), (3, &part3)] {
+        let response = client
+            .get_object()
+            .bucket(MPU_THREE_PARTS_BUCKET)
+            .key(object_key)
+            .part_number(part_number)
+            .send()
+            .await?;
+        let body = response.body.collect().await?.into_bytes();
+        assert_eq!(&body[..], &expected[..], "partNumber={part_number} GET mismatch");
+    }
+
+    // Suffix range (last 64 KiB) resolves inside the trailing part.
+    let suffix_len = 64 * 1024;
+    let suffix = fetch_range(&client, MPU_THREE_PARTS_BUCKET, object_key, &format!("bytes=-{suffix_len}")).await?;
+    assert_eq!(&suffix[..], &original_data[total_size - suffix_len..], "suffix range mismatch");
+
+    info!("Three-part multipart compression partNumber test passed");
+    env.delete_test_bucket(MPU_THREE_PARTS_BUCKET).await?;
+    env.stop_server();
+    Ok(())
+}
+
+const MPU_SSE_COMPRESSION_BUCKET: &str = "compression-mpu-sse-bucket";
+
+async fn start_rustfs_with_compression_and_sse(
+    env: &mut RustFSTestEnvironment,
+) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    use base64::Engine;
+    env.cleanup_existing_processes().await?;
+
+    let binary_path = rustfs_binary_path();
+    let master_key = base64::engine::general_purpose::STANDARD.encode([0x42u8; 32]);
+    // Server output goes to a file inside the per-test temp dir so a failing
+    // run can be diagnosed from the child's logs.
+    let server_log = std::fs::File::create(format!("{}/server.log", env.temp_dir))?;
+    let server_log_err = server_log.try_clone()?;
+    let process = Command::new(&binary_path)
+        .env("RUSTFS_CONSOLE_ENABLE", "false")
+        .env("RUSTFS_COMPRESSION_ENABLED", "true")
+        .env("RUSTFS_COMPRESSION_MULTIPART_ENABLED", "true")
+        .env("RUSTFS_SSE_S3_MASTER_KEY", master_key)
+        .env("RUST_LOG", "rustfs=info,rustfs_ecstore=info")
+        .stdout(std::process::Stdio::from(server_log))
+        .stderr(std::process::Stdio::from(server_log_err))
+        .args([
+            "--address",
+            &env.address,
+            "--access-key",
+            &env.access_key,
+            "--secret-key",
+            &env.secret_key,
+            &env.temp_dir,
+        ])
+        .spawn()?;
+
+    env.process = Some(process);
+
+    info!("Waiting for RustFS server with compression + SSE-S3 enabled on {}", env.address);
+    for i in 0..30 {
+        if TcpStream::connect(&env.address).await.is_ok() {
+            info!("RustFS server is ready after {} attempts", i + 1);
+            return Ok(());
+        }
+        if i == 29 {
+            return Err("RustFS server failed to become ready".into());
+        }
+        sleep(Duration::from_secs(1)).await;
+    }
+    Ok(())
+}
+
+/// SSE-S3 + disk compression multipart: each part is compressed and then encrypted, and every GET
+/// shape must still return the original plaintext bytes. Physical size must shrink because the
+/// compression runs before encryption.
+#[tokio::test]
+#[serial]
+async fn test_compression_multipart_sse_s3_roundtrip() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    use aws_sdk_s3::types::ServerSideEncryption;
+
+    init_logging();
+    info!("Starting SSE-S3 multipart compression roundtrip test");
+
+    let mut env = RustFSTestEnvironment::new().await?;
+    start_rustfs_with_compression_and_sse(&mut env).await?;
+
+    let client = env.create_s3_client();
+    env.create_test_bucket(MPU_SSE_COMPRESSION_BUCKET).await?;
+
+    let object_key = "multipart-sse-compressible.txt";
+    let part1 = generate_compressible_data(MPU_PART1_SIZE);
+    let part2 = generate_compressible_data(MPU_PART2_SIZE);
+    let mut original_data = part1.clone();
+    original_data.extend_from_slice(&part2);
+    let total_size = original_data.len();
+
+    let create = client
+        .create_multipart_upload()
+        .bucket(MPU_SSE_COMPRESSION_BUCKET)
+        .key(object_key)
+        .server_side_encryption(ServerSideEncryption::Aes256)
+        .send()
+        .await?;
+    let upload_id = create.upload_id().ok_or("missing upload id")?.to_string();
+
+    let mut completed_parts = Vec::new();
+    for (i, part) in [&part1, &part2].into_iter().enumerate() {
+        let part_number = (i + 1) as i32;
+        let upload = client
+            .upload_part()
+            .bucket(MPU_SSE_COMPRESSION_BUCKET)
+            .key(object_key)
+            .upload_id(&upload_id)
+            .part_number(part_number)
+            .body(ByteStream::from(part.clone()))
+            .send()
+            .await?;
+        completed_parts.push(
+            CompletedPart::builder()
+                .part_number(part_number)
+                .e_tag(upload.e_tag().unwrap_or_default())
+                .build(),
+        );
+    }
+
+    client
+        .complete_multipart_upload()
+        .bucket(MPU_SSE_COMPRESSION_BUCKET)
+        .key(object_key)
+        .upload_id(&upload_id)
+        .multipart_upload(CompletedMultipartUpload::builder().set_parts(Some(completed_parts)).build())
+        .send()
+        .await?;
+
+    let head_response = client
+        .head_object()
+        .bucket(MPU_SSE_COMPRESSION_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    assert_eq!(
+        head_response.content_length().unwrap_or(0) as usize,
+        total_size,
+        "Content-Length should be the logical object size"
+    );
+    assert_eq!(
+        head_response.server_side_encryption(),
+        Some(&ServerSideEncryption::Aes256),
+        "HEAD must report SSE-S3"
+    );
+
+    let part_files = find_part_files(&env.temp_dir, MPU_SSE_COMPRESSION_BUCKET, object_key);
+    assert!(!part_files.is_empty(), "expected on-disk part files for the multipart object");
+    let total_physical_size: u64 = part_files.iter().filter_map(|p| fs::metadata(p).ok()).map(|m| m.len()).sum();
+    assert!(
+        total_physical_size < (total_size / 2) as u64,
+        "Physical size {total_physical_size} should be well below original size {total_size} (compress-then-encrypt applied)"
+    );
+
+    let get_response = client
+        .get_object()
+        .bucket(MPU_SSE_COMPRESSION_BUCKET)
+        .key(object_key)
+        .send()
+        .await?;
+    let downloaded = get_response.body.collect().await?.into_bytes();
+    assert_eq!(downloaded.len(), total_size);
+    assert_eq!(&downloaded[..], &original_data[..], "SSE-S3 multipart full GET data mismatch");
+
+    // Range crossing the part boundary must decrypt and decompress across parts.
+    let boundary_start = MPU_PART1_SIZE - 64 * 1024;
+    let boundary_end = MPU_PART1_SIZE + 64 * 1024 - 1;
+    let range_crossing = fetch_range(
+        &client,
+        MPU_SSE_COMPRESSION_BUCKET,
+        object_key,
+        &format!("bytes={boundary_start}-{boundary_end}"),
+    )
+    .await?;
+    assert_eq!(
+        &range_crossing[..],
+        &original_data[boundary_start..boundary_end + 1],
+        "SSE-S3 boundary-crossing range mismatch"
+    );
+
+    // partNumber GET for the trailing part.
+    let part2_response = client
+        .get_object()
+        .bucket(MPU_SSE_COMPRESSION_BUCKET)
+        .key(object_key)
+        .part_number(2)
+        .send()
+        .await?;
+    let part2_body = part2_response.body.collect().await?.into_bytes();
+    assert_eq!(&part2_body[..], &part2[..], "SSE-S3 partNumber=2 GET mismatch");
+
+    info!("SSE-S3 multipart compression roundtrip test passed");
+    env.delete_test_bucket(MPU_SSE_COMPRESSION_BUCKET).await?;
+    env.stop_server();
+    Ok(())
+}
@@ -76,6 +76,18 @@ const SOURCE_MTIME_HEADERS: [&str; 2] = ["x-rustfs-source-mtime", "x-minio-sourc
 const SOURCE_REPLICATION_REQUEST_HEADERS: [&str; 2] =
    ["x-rustfs-source-replication-request", "x-minio-source-replication-request"];
 const SOURCE_ETAG_HEADERS: [&str; 2] = ["x-rustfs-source-etag", "x-minio-source-etag"];
+const SOURCE_TAGGING_TIMESTAMP_HEADERS: [&str; 2] = [
+    "x-rustfs-source-replication-tagging-timestamp",
+    "x-minio-source-replication-tagging-timestamp",
+];
+const SOURCE_RETENTION_TIMESTAMP_HEADERS: [&str; 2] = [
+    "x-rustfs-source-replication-retention-timestamp",
+    "x-minio-source-replication-retention-timestamp",
+];
+const SOURCE_LEGALHOLD_TIMESTAMP_HEADERS: [&str; 2] = [
+    "x-rustfs-source-replication-legalhold-timestamp",
+    "x-minio-source-replication-legalhold-timestamp",
+];
 const RESERVED_BUCKET_PREFIXES: [&str; 3] = ["xn--", "sthree-", "amzn-s3-demo-"];
 const RESERVED_BUCKET_SUFFIXES: [&str; 6] = ["-s3alias", "--ol-s3", ".mrap", "--x-s3", "--table-s3", "-an"];

@@ -118,6 +130,25 @@ pub enum FaultAction {
    WrongEtag,
 }

+/// Replication LWW timestamp headers observed on a request, journaled so
+/// sender-side tests can assert what a real target would receive.
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct ReplicationTimestampHeaders {
+    pub tagging: Option<String>,
+    pub retention: Option<String>,
+    pub legalhold: Option<String>,
+}
+
+impl ReplicationTimestampHeaders {
+    fn from_headers(headers: &HeaderMap) -> Self {
+        Self {
+            tagging: header_value(headers, &SOURCE_TAGGING_TIMESTAMP_HEADERS).map(bounded_journal_value),
+            retention: header_value(headers, &SOURCE_RETENTION_TIMESTAMP_HEADERS).map(bounded_journal_value),
+            legalhold: header_value(headers, &SOURCE_LEGALHOLD_TIMESTAMP_HEADERS).map(bounded_journal_value),
+        }
+    }
+}
+
 /// Credential-free request metadata retained for deterministic assertions.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct RequestRecord {
@@ -131,6 +162,7 @@ pub struct RequestRecord {
    pub part_number: Option<i32>,
    pub content_length: Option<u64>,
    pub consumed_bytes: Option<usize>,
+    pub replication_timestamps: ReplicationTimestampHeaders,
    pub fault: Option<FaultAction>,
 }

@@ -536,7 +568,15 @@ impl S3Access for FaultAccess {
            .get(CONTENT_LENGTH)
            .and_then(|value| value.to_str().ok())
            .and_then(|value| value.parse().ok());
-        let fault = record_request(&self.control, operation, context.method().clone(), parsed, content_length);
+        let replication_timestamps = ReplicationTimestampHeaders::from_headers(context.headers());
+        let fault = record_request(
+            &self.control,
+            operation,
+            context.method().clone(),
+            parsed,
+            content_length,
+            replication_timestamps,
+        );
        if let Some(RequestFault {
            action: FaultAction::Status(status),
            ..
@@ -589,6 +629,7 @@ fn record_request(
    method: Method,
    parsed: ParsedRequest,
    content_length: Option<u64>,
+    replication_timestamps: ReplicationTimestampHeaders,
 ) -> Option<RequestFault> {
    let mut state = lock(control);
    let action = parsed
@@ -613,6 +654,7 @@ fn record_request(
        part_number: parsed.part_number,
        content_length,
        consumed_bytes: None,
+        replication_timestamps,
        fault: action.clone(),
    });
    action.map(|action| RequestFault { sequence, action })
@@ -1699,6 +1741,52 @@ mod tests {
            .await?)
    }

+    #[tokio::test]
+    async fn journals_replication_timestamp_headers() -> Result<(), BoxError> {
+        let target = FakeS3Target::start().await?;
+        target.create_bucket("target-bucket");
+        let client = client(&target);
+
+        client
+            .put_object()
+            .bucket("target-bucket")
+            .key("plain")
+            .body(ByteStream::from_static(b"plain"))
+            .send()
+            .await?;
+        client
+            .put_object()
+            .bucket("target-bucket")
+            .key("stamped")
+            .body(ByteStream::from_static(b"stamped"))
+            .customize()
+            .map_request(move |mut request| {
+                let headers = request.headers_mut();
+                headers.insert("x-rustfs-source-replication-tagging-timestamp", "2026-01-02T03:04:05Z");
+                headers.insert("x-minio-source-replication-retention-timestamp", "2026-01-02T03:04:06Z");
+                headers.insert("x-rustfs-source-replication-legalhold-timestamp", "2026-01-02T03:04:07Z");
+                Ok::<_, std::convert::Infallible>(request)
+            })
+            .send()
+            .await?;
+
+        let requests = target.requests();
+        let plain = requests
+            .iter()
+            .find(|record| record.operation == Operation::PutObject && record.key.as_deref() == Some("plain"))
+            .expect("plain PUT must be journaled");
+        assert_eq!(plain.replication_timestamps, ReplicationTimestampHeaders::default());
+
+        let stamped = requests
+            .iter()
+            .find(|record| record.operation == Operation::PutObject && record.key.as_deref() == Some("stamped"))
+            .expect("stamped PUT must be journaled");
+        assert_eq!(stamped.replication_timestamps.tagging.as_deref(), Some("2026-01-02T03:04:05Z"));
+        assert_eq!(stamped.replication_timestamps.retention.as_deref(), Some("2026-01-02T03:04:06Z"));
+        assert_eq!(stamped.replication_timestamps.legalhold.as_deref(), Some("2026-01-02T03:04:07Z"));
+        Ok(())
+    }
+
    macro_rules! assert_sdk_error {
        ($error:expr, $status:expr, $code:expr) => {{
            let error = &$error;
@@ -2985,6 +3073,7 @@ mod tests {
                        part_number: None,
                    },
                    Some(0),
+                    ReplicationTimestampHeaders::default(),
                );
            }
            let records = lock(&control).requests.clone();
@@ -3006,6 +3095,7 @@ mod tests {
                    part_number: None,
                },
                None,
+                ReplicationTimestampHeaders::default(),
            );
            {
                let bounded_records = lock(&bounded_control);
@@ -1828,33 +1828,36 @@ async fn four_node_compressed_inline_fallback() -> TestResult {
    Ok(())
 }

+/// Multipart disk compression is live again, so a compression-enabled cluster classifies multipart objects as compressed and the roundtrip (full GET plus partNumber GET) must still return the original bytes.
+/// Reverting the multipart compression fix must fail this test.
 #[tokio::test]
 #[serial]
-async fn four_node_multipart_ignores_disk_compression_fallback() -> TestResult {
+async fn four_node_multipart_disk_compression_roundtrip() -> TestResult {
    init_logging();

    let collector = OtlpMetricCollector::start().await?;
    let mut cluster = RustFSTestClusterEnvironment::new(4).await?;
    configure_reader_metric_cluster(&mut cluster, &collector);
    cluster.set_env("RUSTFS_COMPRESSION_ENABLED", "true");
+    cluster.set_env("RUSTFS_COMPRESSION_MULTIPART_ENABLED", "true");
    cluster.start().await?;

-    let bucket = "inline-multipart-compression-fallback";
+    let bucket = "inline-multipart-compression-roundtrip";
    cluster.create_test_bucket(bucket).await?;
    let client = cluster.create_s3_client(0)?;
-    let key = "multipart/compression-disabled.txt";
+    let key = "multipart/compressed.txt";
    let (body, second_part, etag) = put_two_part_multipart(&client, bucket, key).await?;

    assert_reader_path(
        &collector,
        &client,
-        ReaderPathExpectation::for_class(ReaderObject::new(bucket, key, &body, etag.as_deref(), None), LEGACY_DUPLEX, MULTIPART),
+        ReaderPathExpectation::for_class(ReaderObject::new(bucket, key, &body, etag.as_deref(), None), LEGACY_DUPLEX, COMPRESSED),
    )
    .await?;
    assert_part_number_reader_path(
        &collector,
        &client,
-        PartNumberReaderPathExpectation::new(bucket, key, &second_part, body.len(), MULTIPART, LEGACY_DUPLEX),
+        PartNumberReaderPathExpectation::new(bucket, key, &second_part, body.len(), COMPRESSED, LEGACY_DUPLEX),
    )
    .await?;

@@ -1871,6 +1874,7 @@ async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls() -> Te
    let sse_master_key = base64::engine::general_purpose::STANDARD.encode([0x42u8; 32]);
    cluster.set_env("RUSTFS_SSE_S3_MASTER_KEY", sse_master_key);
    cluster.set_env("RUSTFS_COMPRESSION_ENABLED", "true");
+    cluster.set_env("RUSTFS_COMPRESSION_MULTIPART_ENABLED", "true");
    configure_mixed_msgpack_cluster(&mut cluster, &collector)?;
    cluster.start().await?;

@@ -1890,14 +1894,21 @@ async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls() -> Te
        ReaderPathExpectation::for_class(
            ReaderObject::new(bucket, multipart_key, &multipart_body, multipart_etag.as_deref(), None),
            LEGACY_DUPLEX,
-            MULTIPART,
+            COMPRESSED,
        ),
    )
    .await?;
    assert_part_number_reader_path(
        &collector,
        &client,
-        PartNumberReaderPathExpectation::new(bucket, multipart_key, &second_part, multipart_body.len(), MULTIPART, LEGACY_DUPLEX),
+        PartNumberReaderPathExpectation::new(
+            bucket,
+            multipart_key,
+            &second_part,
+            multipart_body.len(),
+            COMPRESSED,
+            LEGACY_DUPLEX,
+        ),
    )
    .await?;
    assert_msgpack_decode_observed(&collector, &decode_before).await?;
@@ -2353,7 +2364,11 @@ async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls_during_
    hot_client.create_bucket().bucket(bucket).send().await?;
    put_lifecycle_with_transition_retry(&hot_client, bucket, &tier_name).await?;

-    let key = "transition/mixed-multipart.bin";
+    // `.zip` sits on the disk-compression exclusion list: this test pins
+    // msgpack compat controls across ILM transition, and a compressed object
+    // would classify as `compressed` instead of `remote` (and the warm-tier
+    // read path does not decode compression — tracked separately).
+    let key = "transition/mixed-multipart.zip";
    let (body, second_part, etag) = put_two_part_multipart(&hot_client, bucket, key).await?;
    wait_for_transition(&hot_client, bucket, key, &tier_name).await?;
    assert!(
@@ -97,7 +97,7 @@ async fn start_enforcing_ilm_server(env: &mut LocalKMSTestEnvironment) -> TestRe

    let envs = [
        ("RUSTFS_KMS_ALLOW_INSECURE_DEV_DEFAULTS", "true"),
-        ("RUSTFS_KMS_ENFORCE_SSE_KEY_POLICY", "false"),
+        ("RUSTFS_KMS_ENFORCE_SSE_KEY_POLICY", "true"),
        ("RUSTFS_SCANNER_CYCLE", "1"),
        ("RUSTFS_ILM_PROCESS_TIME", "1"),
        ("RUSTFS_ILM_DEBUG_DAY_SECS", "2"),
@@ -486,7 +486,6 @@ async fn ilm_expiration_on_sse_kms_bucket_under_enforcement() -> TestResult {
 /// depend on scanner scheduling; the 1s scanner cycle stays on as a backstop.
 #[tokio::test]
 #[serial]
-#[ignore = "pins rustfs/rustfs#6025: GET on a transitioned managed-SSE object silently returns corrupt bytes (fails with enforcement on AND off, so it is not an authorization regression); un-ignore with the fix"]
 async fn ilm_transition_on_sse_kms_bucket_under_enforcement_reads_back() -> TestResult {
    init_logging();

@@ -30,7 +30,6 @@ use md5::{Digest as Md5Digest, Md5};
 use rustfs_signer::constants::UNSIGNED_PAYLOAD;
 use rustfs_signer::sign_v4;
 use s3s::Body;
-use serial_test::serial;
 use std::collections::HashMap;
 use std::error::Error;
 use std::io::Cursor;
@@ -356,7 +355,6 @@ async fn run_post_object_policy_case(
 /// smuggles one extra field the policy never declared, and the upload must be
 /// rejected with 403 AccessDenied naming the offending field.
 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_fields_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -484,7 +482,6 @@ async fn test_anonymous_post_object_rejects_fields_missing_from_policy_condition
 /// sends a different one, and the upload must be rejected with 400
 /// InvalidPolicyDocument naming the field.
 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_exact_condition_policy_mismatches()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -689,7 +686,6 @@ async fn test_anonymous_post_object_rejects_exact_condition_policy_mismatches()
 /// one of them with a different value, and the upload must be rejected with
 /// 400 InvalidPolicyDocument naming the mismatched field.
 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_policy_mismatches() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -757,7 +753,6 @@ async fn test_anonymous_post_object_rejects_object_lock_policy_mismatches() -> R
 /// exact values, the form sends a different parameter value, and the upload
 /// must be rejected with 400 InvalidPolicyDocument naming the parameter.
 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sse_kms_policy_mismatches() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -839,7 +834,6 @@ async fn test_anonymous_post_object_rejects_sse_kms_policy_mismatches() -> Resul
 /// NotImplemented (SSE-KMS POST uploads are not implemented), not with a
 /// policy error.
 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sse_kms_params_outside_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -894,7 +888,6 @@ async fn test_anonymous_post_object_rejects_sse_kms_params_outside_policy_condit
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_multipart_control_apis_require_auth() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -968,7 +961,6 @@ async fn test_anonymous_multipart_control_apis_require_auth() -> Result<(), Box<
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_requires_auth() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1002,7 +994,6 @@ async fn test_anonymous_post_object_requires_auth() -> Result<(), Box<dyn std::e
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_honors_success_action_status() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1066,7 +1057,6 @@ async fn test_anonymous_post_object_honors_success_action_status() -> Result<(),
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_honors_success_action_redirect() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1139,7 +1129,6 @@ async fn test_anonymous_post_object_honors_success_action_redirect() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_defaults_to_no_content() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1185,7 +1174,6 @@ async fn test_anonymous_post_object_defaults_to_no_content() -> Result<(), Box<d
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sse_kms() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1232,7 +1220,6 @@ async fn test_anonymous_post_object_rejects_sse_kms() -> Result<(), Box<dyn std:
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_sse_s3() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1290,7 +1277,6 @@ async fn test_anonymous_post_object_accepts_sse_s3() -> Result<(), Box<dyn std::
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_uses_bucket_default_sse_s3() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1363,7 +1349,6 @@ async fn test_anonymous_post_object_uses_bucket_default_sse_s3() -> Result<(), B
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_uses_bucket_default_sse_kms() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1437,7 +1422,6 @@ async fn test_anonymous_post_object_uses_bucket_default_sse_kms() -> Result<(),
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sse_s3_policy_mismatch() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -1488,7 +1472,6 @@ async fn test_anonymous_post_object_rejects_sse_s3_policy_mismatch() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_sse_s3_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1552,7 +1535,6 @@ async fn test_anonymous_post_object_accepts_sse_s3_missing_from_policy_condition
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_storage_class_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1606,7 +1588,6 @@ async fn test_anonymous_post_object_accepts_storage_class_exact_policy_match()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_storage_class_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1657,7 +1638,6 @@ async fn test_anonymous_post_object_rejects_storage_class_missing_from_policy_co
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_invalid_storage_class_value() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -1709,7 +1689,6 @@ async fn test_anonymous_post_object_rejects_invalid_storage_class_value() -> Res
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_checksum_algorithm_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1765,7 +1744,6 @@ async fn test_anonymous_post_object_rejects_checksum_algorithm_missing_from_poli
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_checksum_algorithm_policy_mismatch()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1822,7 +1800,6 @@ async fn test_anonymous_post_object_rejects_checksum_algorithm_policy_mismatch()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_checksum_auxiliary_fields_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1886,7 +1863,6 @@ async fn test_anonymous_post_object_rejects_checksum_auxiliary_fields_missing_fr
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_allows_sse_c_fields_outside_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -1963,7 +1939,6 @@ async fn test_anonymous_post_object_allows_sse_c_fields_outside_policy_condition
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sse_c_exact_policy_mismatch() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -2022,7 +1997,6 @@ async fn test_anonymous_post_object_rejects_sse_c_exact_policy_mismatch() -> Res
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_duplicate_key_form_values() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -2072,7 +2046,6 @@ async fn test_anonymous_post_object_rejects_duplicate_key_form_values() -> Resul
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_invalid_success_action_status() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -2120,7 +2093,6 @@ async fn test_anonymous_post_object_rejects_invalid_success_action_status() -> R
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_invalid_success_action_redirect()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2168,7 +2140,6 @@ async fn test_anonymous_post_object_rejects_invalid_success_action_redirect()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_form_fields_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2223,7 +2194,6 @@ async fn test_anonymous_post_object_rejects_form_fields_missing_from_policy_cond
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_form_fields_covered_by_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2280,7 +2250,6 @@ async fn test_anonymous_post_object_accepts_form_fields_covered_by_policy_condit
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_starts_with_policy_mismatch() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -2335,7 +2304,6 @@ async fn test_anonymous_post_object_rejects_starts_with_policy_mismatch() -> Res
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_content_length_range_violation()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2388,7 +2356,6 @@ async fn test_anonymous_post_object_rejects_content_length_range_violation()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_success_action_status_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2445,7 +2412,6 @@ async fn test_anonymous_post_object_accepts_success_action_status_exact_policy_m
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_success_action_redirect_policy_mismatch()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2502,7 +2468,6 @@ async fn test_anonymous_post_object_rejects_success_action_redirect_policy_misma
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_success_action_redirect_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2568,7 +2533,6 @@ async fn test_anonymous_post_object_accepts_success_action_redirect_exact_policy
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_success_action_redirect_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2621,7 +2585,6 @@ async fn test_anonymous_post_object_rejects_success_action_redirect_missing_from
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_metadata_field_covered_by_starts_with()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2676,7 +2639,6 @@ async fn test_anonymous_post_object_accepts_metadata_field_covered_by_starts_wit
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_content_type_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2734,7 +2696,6 @@ async fn test_anonymous_post_object_accepts_content_type_field_exact_policy_matc
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_content_type_field_covered_by_starts_with()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2792,7 +2753,6 @@ async fn test_anonymous_post_object_accepts_content_type_field_covered_by_starts
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_content_disposition_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2850,7 +2810,6 @@ async fn test_anonymous_post_object_accepts_content_disposition_field_exact_poli
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_cache_control_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2908,7 +2867,6 @@ async fn test_anonymous_post_object_accepts_cache_control_field_exact_policy_mat
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_content_language_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -2966,7 +2924,6 @@ async fn test_anonymous_post_object_accepts_content_language_field_exact_policy_
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_content_encoding_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3024,7 +2981,6 @@ async fn test_anonymous_post_object_accepts_content_encoding_field_exact_policy_
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_website_redirect_location_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3082,7 +3038,6 @@ async fn test_anonymous_post_object_accepts_website_redirect_location_exact_poli
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_expires_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3140,7 +3095,6 @@ async fn test_anonymous_post_object_accepts_expires_field_exact_policy_match()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_retention_without_permission()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3196,7 +3150,6 @@ async fn test_anonymous_post_object_rejects_object_lock_retention_without_permis
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_retention_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3256,7 +3209,6 @@ async fn test_anonymous_post_object_rejects_object_lock_retention_missing_from_p
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_legal_hold_without_permission()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3309,7 +3261,6 @@ async fn test_anonymous_post_object_rejects_object_lock_legal_hold_without_permi
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_legal_hold_policy_mismatch()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3368,7 +3319,6 @@ async fn test_anonymous_post_object_rejects_object_lock_legal_hold_policy_mismat
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_object_lock_legal_hold_missing_from_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3426,7 +3376,6 @@ async fn test_anonymous_post_object_rejects_object_lock_legal_hold_missing_from_
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_tagging_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3492,7 +3441,6 @@ async fn test_anonymous_post_object_accepts_tagging_field_exact_policy_match()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_accepts_metadata_field_exact_policy_match()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3551,7 +3499,6 @@ async fn test_anonymous_post_object_accepts_metadata_field_exact_policy_match()
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_allows_x_ignore_fields_outside_policy_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3604,7 +3551,6 @@ async fn test_anonymous_post_object_allows_x_ignore_fields_outside_policy_condit
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_sigv4_date_policy_mismatch() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -3657,7 +3603,6 @@ async fn test_anonymous_post_object_rejects_sigv4_date_policy_mismatch() -> Resu
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_mismatched_bucket_form_field() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -3712,7 +3657,6 @@ async fn test_anonymous_post_object_rejects_mismatched_bucket_form_field() -> Re
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_multiple_bucket_values() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -3764,7 +3708,6 @@ async fn test_anonymous_post_object_rejects_multiple_bucket_values() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_post_object_rejects_extra_content_disposition_field()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3820,7 +3763,6 @@ async fn test_anonymous_post_object_rejects_extra_content_disposition_field()
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_tar_entries_with_prefix_headers()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3891,7 +3833,6 @@ async fn test_signed_put_object_extract_expands_tar_entries_with_prefix_headers(
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_request_metadata_on_extracted_objects()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -3956,7 +3897,6 @@ async fn test_signed_put_object_extract_preserves_request_metadata_on_extracted_
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_sse_s3_and_redirect() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4004,7 +3944,6 @@ async fn test_signed_put_object_extract_preserves_sse_s3_and_redirect() -> Resul
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_storage_class() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4047,7 +3986,6 @@ async fn test_signed_put_object_extract_preserves_storage_class() -> Result<(),
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_rejects_invalid_storage_class() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4083,7 +4021,6 @@ async fn test_signed_put_object_extract_rejects_invalid_storage_class() -> Resul
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_rejects_write_offset_bytes_header() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4137,7 +4074,6 @@ async fn test_signed_put_object_rejects_write_offset_bytes_header() -> Result<()
 }

 #[tokio::test]
-#[serial]
 async fn test_raw_signed_put_object_write_offset_bytes_returns_minio_compatible_error_body()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -4176,7 +4112,6 @@ async fn test_raw_signed_put_object_write_offset_bytes_returns_minio_compatible_
 }

 #[tokio::test]
-#[serial]
 async fn test_anonymous_put_object_write_offset_bytes_returns_minio_compatible_error_body()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -4235,7 +4170,6 @@ async fn test_anonymous_put_object_write_offset_bytes_returns_minio_compatible_e
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_uses_bucket_default_sse_s3() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4300,7 +4234,6 @@ async fn test_signed_put_object_extract_uses_bucket_default_sse_s3() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_rejects_bucket_default_sse_kms() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4356,7 +4289,6 @@ async fn test_signed_put_object_extract_rejects_bucket_default_sse_kms() -> Resu
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_sse_c() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4421,7 +4353,6 @@ async fn test_signed_put_object_extract_preserves_sse_c() -> Result<(), Box<dyn
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_object_lock_legal_hold() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -4476,7 +4407,6 @@ async fn test_signed_put_object_extract_preserves_object_lock_legal_hold() -> Re
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_object_lock_retention() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -4536,7 +4466,6 @@ async fn test_signed_put_object_extract_preserves_object_lock_retention() -> Res
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_pax_retention_overrides_request_retention()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -4600,7 +4529,6 @@ async fn test_signed_put_object_extract_pax_retention_overrides_request_retentio
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_returns_archive_etag() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4634,7 +4562,6 @@ async fn test_signed_put_object_extract_returns_archive_etag() -> Result<(), Box
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_entry_mtime() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -4670,7 +4597,6 @@ async fn test_signed_put_object_extract_preserves_entry_mtime() -> Result<(), Bo
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_pax_metadata_and_version_id()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -4724,7 +4650,6 @@ async fn test_signed_put_object_extract_preserves_pax_metadata_and_version_id()
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_authorizes_each_pax_privilege_and_retention_conditions()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -5034,7 +4959,6 @@ async fn test_signed_put_object_extract_authorizes_each_pax_privilege_and_retent
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_accepts_compat_header() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5076,7 +5000,6 @@ async fn test_signed_put_object_extract_accepts_compat_header() -> Result<(), Bo
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_preserves_directory_markers_by_default()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -5137,7 +5060,6 @@ async fn test_signed_put_object_extract_preserves_directory_markers_by_default()
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_tar_gz_archive() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5189,7 +5111,6 @@ async fn test_signed_put_object_extract_expands_tar_gz_archive() -> Result<(), B
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_tgz_archive() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5241,7 +5162,6 @@ async fn test_signed_put_object_extract_expands_tgz_archive() -> Result<(), Box<
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_tbz2_archive() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5293,7 +5213,6 @@ async fn test_signed_put_object_extract_expands_tbz2_archive() -> Result<(), Box
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_txz_archive() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5345,7 +5264,6 @@ async fn test_signed_put_object_extract_expands_txz_archive() -> Result<(), Box<
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_skips_invalid_entry_when_ignore_errors_enabled()
 -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();
@@ -5419,7 +5337,6 @@ async fn test_signed_put_object_extract_skips_invalid_entry_when_ignore_errors_e
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_normalizes_prefix_header_value() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5462,7 +5379,6 @@ async fn test_signed_put_object_extract_normalizes_prefix_header_value() -> Resu
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_expands_tzst_archive() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -5514,7 +5430,6 @@ async fn test_signed_put_object_extract_expands_tzst_archive() -> Result<(), Box
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_rejects_missing_archive_extension() -> Result<(), Box<dyn std::error::Error + Send + Sync>>
 {
    init_logging();
@@ -5548,7 +5463,6 @@ async fn test_signed_put_object_extract_rejects_missing_archive_extension() -> R
 }

 #[tokio::test]
-#[serial]
 async fn test_signed_put_object_extract_rejects_invalid_tar_gz_payload() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    init_logging();

@@ -33,7 +33,6 @@ use aws_sdk_s3::types::{
    ObjectLockMode, ObjectLockRetentionMode,
 };
 use chrono::{DateTime, Duration, Utc};
-use serial_test::serial;
 use tracing::info;

 /// Initialize test logging
@@ -107,7 +106,6 @@ fn parse_s3_datetime(value: &aws_sdk_s3::primitives::DateTime) -> DateTime<Utc>
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_delete_object_blocked_by_compliance_retention() {
    init_logging();
    info!("🧪 Test: DeleteObject blocked by COMPLIANCE retention");
@@ -145,7 +143,6 @@ async fn test_delete_object_blocked_by_compliance_retention() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_blocked_by_governance_without_bypass() {
    init_logging();
    info!("🧪 Test: DeleteObject blocked by GOVERNANCE retention without bypass");
@@ -175,7 +172,6 @@ async fn test_delete_object_blocked_by_governance_without_bypass() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_allowed_by_governance_with_bypass() {
    init_logging();
    info!("🧪 Test: DeleteObject allowed by GOVERNANCE retention with bypass");
@@ -215,7 +211,6 @@ async fn test_delete_object_allowed_by_governance_with_bypass() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_creates_delete_marker_for_retained_current_version() {
    init_logging();
    info!("🧪 Test: DeleteObject creates delete marker for retained current version");
@@ -266,7 +261,6 @@ async fn test_delete_object_creates_delete_marker_for_retained_current_version()
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_blocked_by_legal_hold() {
    init_logging();
    info!("🧪 Test: DeleteObject blocked by Legal Hold");
@@ -299,7 +293,6 @@ async fn test_delete_object_blocked_by_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_allowed_with_legal_hold_off() {
    init_logging();
    info!("🧪 Test: DeleteObject allowed with Legal Hold OFF");
@@ -335,7 +328,6 @@ async fn test_delete_object_allowed_with_legal_hold_off() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_after_legal_hold_removed() {
    init_logging();
    info!("🧪 Test: DeleteObject succeeds after Legal Hold is removed");
@@ -369,7 +361,6 @@ async fn test_delete_object_after_legal_hold_removed() {
 }

 #[tokio::test]
-#[serial]
 async fn test_get_object_legal_hold_returns_updated_status() {
    init_logging();
    info!("🧪 Test: GetObjectLegalHold returns updated status");
@@ -425,7 +416,6 @@ async fn test_get_object_legal_hold_returns_updated_status() {
 }

 #[tokio::test]
-#[serial]
 async fn test_get_object_retention_returns_configured_values() {
    init_logging();
    info!("🧪 Test: GetObjectRetention returns configured values");
@@ -476,7 +466,6 @@ async fn test_get_object_retention_returns_configured_values() {
 // creating a new current version. The lock protects the existing version
 // from deletion; it never blocks new versions.
 #[tokio::test]
-#[serial]
 async fn test_put_object_overwrite_creates_new_version_under_legal_hold() {
    init_logging();
    info!("🧪 Test: PutObject overwrite of a legal-hold version creates a new version");
@@ -561,7 +550,6 @@ async fn test_put_object_overwrite_creates_new_version_under_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_copy_object_applies_requested_legal_hold() {
    init_logging();
    info!("🧪 Test: CopyObject applies requested Legal Hold");
@@ -613,7 +601,6 @@ async fn test_copy_object_applies_requested_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_copy_object_does_not_inherit_source_legal_hold() {
    init_logging();
    info!("🧪 Test: CopyObject does not inherit source Legal Hold");
@@ -707,7 +694,6 @@ async fn test_copy_object_does_not_inherit_source_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_copy_object_overwrite_creates_new_version_under_legal_hold() {
    init_logging();
    info!("🧪 Test: CopyObject overwrite of a legal-hold destination creates a new version");
@@ -787,7 +773,6 @@ async fn test_copy_object_overwrite_creates_new_version_under_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_create_multipart_upload_applies_requested_legal_hold() {
    init_logging();
    info!("🧪 Test: CreateMultipartUpload applies requested Legal Hold");
@@ -853,7 +838,6 @@ async fn test_create_multipart_upload_applies_requested_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_create_multipart_upload_creates_new_version_under_compliance_retention() {
    init_logging();
    info!("🧪 Test: CreateMultipartUpload over a COMPLIANCE-retained key creates a new version");
@@ -933,7 +917,6 @@ async fn test_create_multipart_upload_creates_new_version_under_compliance_reten
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_completed_multipart_object_blocked_by_legal_hold() {
    init_logging();
    info!("🧪 Test: Delete completed multipart object blocked by Legal Hold");
@@ -993,7 +976,6 @@ async fn test_delete_completed_multipart_object_blocked_by_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_completed_multipart_object_blocked_by_retention() {
    init_logging();
    info!("🧪 Test: Delete completed multipart object blocked by retention");
@@ -1055,7 +1037,6 @@ async fn test_delete_completed_multipart_object_blocked_by_retention() {
 }

 #[tokio::test]
-#[serial]
 async fn test_complete_multipart_upload_creates_new_version_under_legal_hold() {
    init_logging();
    info!("🧪 Test: CompleteMultipartUpload creates a new version when the current version is under Legal Hold");
@@ -1135,7 +1116,6 @@ async fn test_complete_multipart_upload_creates_new_version_under_legal_hold() {
 }

 #[tokio::test]
-#[serial]
 async fn test_complete_multipart_upload_creates_new_version_under_compliance_retention() {
    init_logging();
    info!("🧪 Test: CompleteMultipartUpload creates a new version when the current version is under COMPLIANCE retention");
@@ -1209,7 +1189,6 @@ async fn test_complete_multipart_upload_creates_new_version_under_compliance_ret
 }

 #[tokio::test]
-#[serial]
 async fn test_write_paths_require_put_object_legal_hold_permission() {
    init_logging();
    info!("🧪 Test: write paths require PutObjectLegalHold permission");
@@ -1273,7 +1252,6 @@ async fn test_write_paths_require_put_object_legal_hold_permission() {
 }

 #[tokio::test]
-#[serial]
 async fn test_write_paths_require_put_object_retention_permission() {
    init_logging();
    info!("🧪 Test: write paths require PutObjectRetention permission");
@@ -1345,7 +1323,6 @@ async fn test_write_paths_require_put_object_retention_permission() {
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_delete_objects_mixed_locked_unlocked() {
    init_logging();
    info!("🧪 Test: DeleteObjects with mixed locked and unlocked objects");
@@ -1427,7 +1404,6 @@ async fn test_delete_objects_mixed_locked_unlocked() {
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_put_retention_compliance_cannot_shorten() {
    init_logging();
    info!("🧪 Test: PutObjectRetention cannot shorten COMPLIANCE retention");
@@ -1468,7 +1444,6 @@ async fn test_put_retention_compliance_cannot_shorten() {
 }

 #[tokio::test]
-#[serial]
 async fn test_put_retention_compliance_can_extend() {
    init_logging();
    info!("🧪 Test: PutObjectRetention can extend COMPLIANCE retention");
@@ -1509,7 +1484,6 @@ async fn test_put_retention_compliance_can_extend() {
 }

 #[tokio::test]
-#[serial]
 async fn test_put_retention_governance_extend_without_bypass() {
    init_logging();
    info!("🧪 Test: PutObjectRetention on GOVERNANCE can extend without bypass");
@@ -1553,7 +1527,6 @@ async fn test_put_retention_governance_extend_without_bypass() {
 }

 #[tokio::test]
-#[serial]
 async fn test_put_retention_governance_shorten_requires_bypass() {
    init_logging();
    info!("🧪 Test: PutObjectRetention on GOVERNANCE requires bypass to shorten");
@@ -1615,7 +1588,6 @@ async fn test_put_retention_governance_shorten_requires_bypass() {
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_default_retention_applied_to_new_objects() {
    init_logging();
    info!("🧪 Test: Default retention is applied to new objects");
@@ -1685,7 +1657,6 @@ async fn test_default_retention_applied_to_new_objects() {
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_object_creates_delete_marker_for_default_retained_current_version() {
    init_logging();
    info!("🧪 Test: DeleteObject creates delete marker for default-retained current version");
@@ -1770,7 +1741,6 @@ async fn test_delete_object_creates_delete_marker_for_default_retained_current_v
 }

 #[tokio::test]
-#[serial]
 async fn test_put_copy_and_multipart_reject_incomplete_retention_headers() {
    init_logging();
    info!("🧪 Test: write paths reject incomplete Object Lock retention headers");
@@ -1869,7 +1839,6 @@ async fn test_put_copy_and_multipart_reject_incomplete_retention_headers() {
 }

 #[tokio::test]
-#[serial]
 async fn test_copy_object_retention_uses_destination_policy() {
    init_logging();
    info!("🧪 Test: CopyObject retention follows destination policy");
@@ -2051,7 +2020,6 @@ async fn test_copy_object_retention_uses_destination_policy() {
 }

 #[tokio::test]
-#[serial]
 async fn test_multipart_default_retention_fixed_at_create() {
    init_logging();
    info!("🧪 Test: multipart default retention is fixed at CreateMultipartUpload");
@@ -2122,7 +2090,6 @@ async fn test_multipart_default_retention_fixed_at_create() {
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_unretained_object_lock_object_delete_and_bucket_cleanup() {
    init_logging();
    info!("🧪 Test: Unretained Object Lock object delete and bucket cleanup (Issue #5339)");
@@ -2243,7 +2210,6 @@ async fn test_unretained_object_lock_object_delete_and_bucket_cleanup() {
 }

 #[tokio::test]
-#[serial]
 async fn test_versioning_auto_enabled_with_object_lock() {
    init_logging();
    info!("🧪 Test: Versioning is auto-enabled when Object Lock is configured");
@@ -2302,7 +2268,6 @@ async fn test_versioning_auto_enabled_with_object_lock() {
 // ============================================================================

 #[tokio::test]
-#[serial]
 async fn test_error_message_distinguishes_legal_hold_from_retention() {
    init_logging();
    info!("🧪 Test: Error messages distinguish Legal Hold from Retention");
@@ -60,7 +60,6 @@ use rustfs_signer::constants::UNSIGNED_PAYLOAD;
 use rustfs_signer::sign_v4;
 use s3s::Body;
 use s3s::header::X_AMZ_REPLICATION_STATUS;
-use serial_test::serial;
 use sha2::{Digest, Sha256};
 use std::collections::BTreeMap;
 use std::convert::Infallible;
@@ -2506,7 +2505,6 @@ async fn build_replication_pair(
 /// metadata was inherited wholesale from the source, so the scanner heal pass
 /// skipped it too — no PENDING/FAILED marker meant nothing to re-drive).
 #[tokio::test]
-#[serial]
 async fn test_copy_object_replicates_to_target() -> TestResult {
    init_logging();

@@ -2555,7 +2553,6 @@ async fn test_copy_object_replicates_to_target() -> TestResult {
 /// independent object; every member must replicate to the remote target like a
 /// regular PUT (MinIO PutObjectExtract parity).
 #[tokio::test]
-#[serial]
 async fn test_snowball_extract_replicates_members_to_target() -> TestResult {
    init_logging();

@@ -2601,7 +2598,6 @@ async fn test_snowball_extract_replicates_members_to_target() -> TestResult {
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_succeeds_with_remote_target() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2638,7 +2634,6 @@ async fn test_replication_check_succeeds_with_remote_target() -> Result<(), Box<
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_rejects_target_without_object_lock() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2692,7 +2687,6 @@ async fn test_replication_check_rejects_target_without_object_lock() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_unversioned_source_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2731,7 +2725,6 @@ async fn test_set_remote_target_rejects_unversioned_source_bucket() -> Result<()
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_rejects_unversioned_source_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2755,7 +2748,6 @@ async fn test_replication_check_rejects_unversioned_source_bucket() -> Result<()
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_rejects_missing_replication_config() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2779,7 +2771,6 @@ async fn test_replication_check_rejects_missing_replication_config() -> Result<(
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_rejects_invalid_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2798,7 +2789,6 @@ async fn test_replication_check_rejects_invalid_bucket() -> Result<(), Box<dyn E
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_same_bucket_on_same_deployment() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2842,7 +2832,6 @@ async fn test_set_remote_target_rejects_same_bucket_on_same_deployment() -> Resu
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_unversioned_target_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2876,7 +2865,6 @@ async fn test_set_remote_target_rejects_unversioned_target_bucket() -> Result<()
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_update_requires_arn() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -2928,7 +2916,6 @@ async fn test_set_remote_target_update_requires_arn() -> Result<(), Box<dyn Erro
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_update_rejects_missing_target() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3017,7 +3004,6 @@ async fn fetch_single_target(
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_partial_update_preserves_credentials() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3103,7 +3089,6 @@ async fn test_set_remote_target_partial_update_preserves_credentials() -> Result
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_invalid_target_url() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3145,7 +3130,6 @@ async fn test_set_remote_target_rejects_invalid_target_url() -> Result<(), Box<d
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_self_signed_https_target_without_skip_tls_verify()
 -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();
@@ -3230,7 +3214,6 @@ async fn test_set_remote_target_rejects_self_signed_https_target_without_skip_tl
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_allows_self_signed_https_target_with_skip_tls_verify() -> Result<(), Box<dyn Error + Send + Sync>>
 {
    init_logging();
@@ -3342,7 +3325,6 @@ async fn test_set_remote_target_allows_self_signed_https_target_with_skip_tls_ve
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_rejects_private_ca_https_target_without_ca_cert_pem() -> Result<(), Box<dyn Error + Send + Sync>>
 {
    init_logging();
@@ -3427,7 +3409,6 @@ async fn test_set_remote_target_rejects_private_ca_https_target_without_ca_cert_
 }

 #[tokio::test]
-#[serial]
 async fn test_set_remote_target_allows_private_ca_https_target_with_ca_cert_pem() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3518,7 +3499,6 @@ async fn test_set_remote_target_allows_private_ca_https_target_with_ca_cert_pem(
 }

 #[tokio::test]
-#[serial]
 async fn test_list_remote_targets_rejects_empty_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3538,7 +3518,6 @@ async fn test_list_remote_targets_rejects_empty_bucket() -> Result<(), Box<dyn E
 }

 #[tokio::test]
-#[serial]
 async fn test_list_remote_targets_rejects_invalid_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3557,7 +3536,6 @@ async fn test_list_remote_targets_rejects_invalid_bucket() -> Result<(), Box<dyn
 }

 #[tokio::test]
-#[serial]
 async fn test_remove_remote_target_rejects_missing_target() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3598,7 +3576,6 @@ async fn test_remove_remote_target_rejects_missing_target() -> Result<(), Box<dy
 }

 #[tokio::test]
-#[serial]
 async fn test_remove_remote_target_rejects_missing_arn() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3623,7 +3600,6 @@ async fn test_remove_remote_target_rejects_missing_arn() -> Result<(), Box<dyn E
 }

 #[tokio::test]
-#[serial]
 async fn test_remove_remote_target_rejects_invalid_bucket() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3647,7 +3623,6 @@ async fn test_remove_remote_target_rejects_invalid_bucket() -> Result<(), Box<dy
 }

 #[tokio::test]
-#[serial]
 async fn test_remove_remote_target_rejects_target_used_by_replication() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3687,7 +3662,6 @@ async fn test_remove_remote_target_rejects_target_used_by_replication() -> Resul
 }

 #[tokio::test]
-#[serial]
 async fn test_delete_bucket_replication_removes_remote_target() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3737,7 +3711,6 @@ async fn test_delete_bucket_replication_removes_remote_target() -> Result<(), Bo
 }

 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_replicates_put_object_issue_2539() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -3779,7 +3752,6 @@ async fn test_bucket_replication_replicates_put_object_issue_2539() -> Result<()
 }

 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_converges_delete_marker_and_version_purge() -> TestResult {
    init_logging();

@@ -3878,7 +3850,6 @@ async fn test_bucket_replication_converges_delete_marker_and_version_purge() ->
 }

 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_disabled_delete_marker_does_not_propagate() -> TestResult {
    init_logging();

@@ -3965,7 +3936,6 @@ async fn test_bucket_replication_disabled_delete_marker_does_not_propagate() ->
 /// interoperability profile for a runner that provisions MinIO credentials
 /// and a reachable endpoint.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_acceptance_matrix_local_dual_targets() -> TestResult {
    init_logging();

@@ -4293,7 +4263,6 @@ async fn test_bucket_replication_acceptance_matrix_local_dual_targets() -> TestR
 }

 #[tokio::test]
-#[serial]
 async fn test_single_bucket_multipart_replication_fans_out_to_multiple_targets() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -4462,7 +4431,6 @@ async fn test_repl17_failure_observation_helpers() -> TestResult {
 /// the replica is decryptable only with the original customer key. The
 /// backlog#1291 property still holds: never a silent plaintext replica.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_c_contract() -> TestResult {
    init_logging();

@@ -4540,7 +4508,6 @@ async fn test_bucket_replication_sse_c_contract() -> TestResult {
 /// part — part boundaries and the encrypted-multipart marker survive so the
 /// replica decrypts each part with its part-derived nonce.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_c_multipart_passthrough() -> TestResult {
    init_logging();

@@ -4657,7 +4624,6 @@ async fn test_bucket_replication_sse_c_multipart_passthrough() -> TestResult {
 /// (independent KMS, so success proves target-owned envelopes), preserved
 /// source ETag, and a version that stays stable across scanner cycles.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_s3_contract() -> TestResult {
    init_logging();
    assert_managed_sse_replicates_and_reencrypts("sse-s3", false).await
@@ -4667,7 +4633,6 @@ async fn test_bucket_replication_sse_s3_contract() -> TestResult {
 /// fail closed — replication FAILED, and no plaintext (or any) replica ever
 /// materializes on the target.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_s3_fails_closed_without_target_kms() -> TestResult {
    init_logging();

@@ -4711,7 +4676,6 @@ async fn test_bucket_replication_sse_s3_fails_closed_without_target_kms() -> Tes
 /// the ETag comparison sees the preserved source ETag on the replica and does
 /// not rewrite it, so the replica's version stays stable through the resync.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_s3_resync_converges() -> TestResult {
    init_logging();

@@ -4768,7 +4732,6 @@ async fn test_bucket_replication_sse_s3_resync_converges() -> TestResult {
 /// re-encrypts under its own default key. The independent-KMS pair proves the
 /// replica's envelope is target-owned.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_kms_contract() -> TestResult {
    init_logging();
    assert_managed_sse_replicates_and_reencrypts("sse-kms", true).await
@@ -4779,7 +4742,6 @@ async fn test_bucket_replication_sse_kms_contract() -> TestResult {
 /// carries the full header set (SSE intent, content-type, user metadata) and
 /// the completed replica preserves the source's multipart ETag.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_sse_s3_multipart_reencrypts() -> TestResult {
    init_logging();

@@ -4873,7 +4835,6 @@ async fn test_bucket_replication_sse_s3_multipart_reencrypts() -> TestResult {
 /// still-running source's data scanner (short cycle via [`FAST_SCANNER_ENV`])
 /// re-drives the failed objects once the target is reachable again.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_recovers_after_target_outage() -> TestResult {
    init_logging();

@@ -4953,7 +4914,6 @@ async fn test_bucket_replication_recovers_after_target_outage() -> TestResult {
 /// must settle back to zero even though the historical failed counter remains
 /// non-zero.
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_backlog_metrics_observe_outage_and_recovery() -> TestResult {
    init_logging();

@@ -5087,7 +5047,6 @@ async fn test_bucket_replication_backlog_metrics_observe_outage_and_recovery() -
 /// must converge every persisted failure, including the replayed delete marker
 /// (whose replication decision is re-derived from the live config).
 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_replays_failed_entries_after_source_restart() -> TestResult {
    init_logging();

@@ -5179,7 +5138,6 @@ async fn test_bucket_replication_replays_failed_entries_after_source_restart() -
 }

 #[tokio::test]
-#[serial]
 async fn test_bucket_replication_replayed_delete_marker_preserves_source_mtime_without_source_restart() -> TestResult {
    init_logging();

@@ -5249,7 +5207,6 @@ async fn test_bucket_replication_replayed_delete_marker_preserves_source_mtime_w
 }

 #[tokio::test]
-#[serial]
 async fn test_sequential_bucket_replication_succeeds_for_multiple_buckets() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -5293,7 +5250,6 @@ async fn test_sequential_bucket_replication_succeeds_for_multiple_buckets() -> R
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_recovers_after_runtime_target_cache_is_cleared() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -5337,7 +5293,6 @@ async fn test_replication_recovers_after_runtime_target_cache_is_cleared() -> Re
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_allows_self_signed_https_with_skip_tls_verify_real_dual_node() -> TestResult {
    init_logging();

@@ -5416,7 +5371,6 @@ async fn test_site_replication_allows_self_signed_https_with_skip_tls_verify_rea
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_allows_private_ca_https_with_ca_cert_pem_real_dual_node() -> TestResult {
    init_logging();

@@ -5495,7 +5449,6 @@ async fn test_site_replication_allows_private_ca_https_with_ca_cert_pem_real_dua
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_resync_lifecycle_survives_real_server_restart() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();
    let resync_process_env = [
@@ -5715,7 +5668,6 @@ async fn test_site_replication_resync_lifecycle_survives_real_server_restart() -
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_edit_and_status_peer_state_real_three_node() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -5964,7 +5916,6 @@ async fn test_site_replication_edit_and_status_peer_state_real_three_node() -> R
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_remove_all_real_dual_node() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -6084,7 +6035,6 @@ async fn test_site_replication_remove_all_real_dual_node() -> Result<(), Box<dyn
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_state_edit_fresh_and_stale_real_dual_node() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -6193,7 +6143,6 @@ async fn test_site_replication_state_edit_fresh_and_stale_real_dual_node() -> Re
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_replicates_object_with_bucket_versioning_real_dual_node() -> TestResult {
    init_logging();

@@ -6284,7 +6233,6 @@ async fn test_site_replication_replicates_object_with_bucket_versioning_real_dua
 /// receiver was dropped with only a debug line, while `replicate status` still reported
 /// "1/1 Buckets in sync" because both configs were byte-identical.
 #[tokio::test]
-#[serial]
 async fn test_site_replication_config_broadcast_keeps_reverse_direction_real_dual_node() -> TestResult {
    init_logging();

@@ -6423,7 +6371,6 @@ async fn wait_for_site_replication_rule(
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_active_active_converges_without_loops_real_dual_node() -> TestResult {
    init_logging();

@@ -6741,7 +6688,6 @@ async fn test_site_replication_active_active_converges_without_loops_real_dual_n
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_replicates_policy_backed_user_access_real_dual_node() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -6829,7 +6775,6 @@ async fn test_site_replication_replicates_policy_backed_user_access_real_dual_no
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_replicates_group_policy_backed_access_real_dual_node() -> Result<(), Box<dyn Error + Send + Sync>>
 {
    init_logging();
@@ -6920,7 +6865,6 @@ async fn test_site_replication_replicates_group_policy_backed_access_real_dual_n
 }

 #[tokio::test]
-#[serial]
 async fn test_service_account_policy_from_accountinfo_round_trips_real_single_node() -> TestResult {
    init_logging();

@@ -6972,7 +6916,6 @@ async fn test_service_account_policy_from_accountinfo_round_trips_real_single_no
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_replicates_multiple_service_accounts_real_dual_node() -> Result<(), Box<dyn Error + Send + Sync>> {
    init_logging();

@@ -7073,7 +7016,6 @@ async fn test_site_replication_replicates_multiple_service_accounts_real_dual_no
 }

 #[tokio::test]
-#[serial]
 async fn test_site_replication_replicates_service_accounts_created_from_sts_session_real_dual_node() -> TestResult {
    init_logging();

@@ -7214,7 +7156,6 @@ async fn wait_for_target_request_version_id(
 }

 #[tokio::test]
-#[serial]
 async fn test_bucket_resync_restart_revisits_objects_before_out_of_order_checkpoint() -> TestResult {
    init_logging();

@@ -7333,7 +7274,6 @@ async fn test_bucket_resync_restart_revisits_objects_before_out_of_order_checkpo
 /// CreateMultipartUpload (the version is decided at initiate time) must both
 /// carry the source version as `?versionId=`.
 #[tokio::test]
-#[serial]
 async fn test_replication_put_and_create_multipart_carry_source_version_id_query() -> TestResult {
    init_logging();

@@ -7448,7 +7388,6 @@ async fn test_replication_put_and_create_multipart_carry_source_version_id_query
 /// flow to the onward bucket, proving B's outbound replication and scanner
 /// are live.
 #[tokio::test]
-#[serial]
 async fn test_scanner_never_cascades_inbound_replicas() -> TestResult {
    init_logging();

@@ -7529,7 +7468,6 @@ async fn test_scanner_never_cascades_inbound_replicas() -> TestResult {
 /// version ids and still mint its own there — the check must not report OK
 /// while multipart deletes and heals would silently miss.
 #[tokio::test]
-#[serial]
 async fn test_replication_check_flags_multipart_only_version_minting_target() -> TestResult {
    init_logging();

@@ -7602,7 +7540,6 @@ async fn test_replication_check_flags_multipart_only_version_minting_target() ->
 }

 #[tokio::test]
-#[serial]
 async fn test_replication_check_aborts_failed_multipart_probes() -> TestResult {
    init_logging();

@@ -7765,7 +7702,6 @@ async fn test_replication_check_aborts_failed_multipart_probes() -> TestResult {
 /// BucketRemoteTargetVersionMismatch — while still cleaning up the probe
 /// object via the version id the target actually assigned.
 #[tokio::test]
-#[serial]
 async fn test_replication_check_flags_version_minting_target() -> TestResult {
    init_logging();

@@ -8006,7 +7942,6 @@ async fn wait_for_target_marker_purged(
 /// the target forever. Contract under test: a failed purge attempt is retried
 /// within the watch window and converges once the fault clears.
 #[tokio::test]
-#[serial]
 async fn test_delayed_delete_marker_purge_retries_after_transient_target_failure() -> TestResult {
    init_logging();
    let source_bucket = "delayed-purge-retry-src";
@@ -8066,7 +8001,6 @@ async fn test_delayed_delete_marker_purge_retries_after_transient_target_failure
 /// with an idempotent 204, which used to look like success and strand the
 /// real marker on the target forever.
 #[tokio::test]
-#[serial]
 async fn test_delayed_delete_marker_purge_uses_target_assigned_version() -> TestResult {
    init_logging();
    let source_bucket = "delayed-purge-mint-src";
@@ -8099,7 +8033,6 @@ async fn test_delayed_delete_marker_purge_uses_target_assigned_version() -> Test
 /// replayed purge succeeds, the entry must be acknowledged instead of being
 /// retained as Missed forever.
 #[tokio::test]
-#[serial]
 async fn test_delayed_delete_marker_purge_exhaustion_persists_to_mrf_and_replays_on_restart() -> TestResult {
    init_logging();
    let source_bucket = "delayed-purge-mrf-src";
@@ -8236,7 +8169,6 @@ async fn build_scanner_compensation_pair(
 /// nil-version objects entirely (`scanner_folder.rs` heal_replication), so it
 /// must NEVER be compensated.
 #[tokio::test]
-#[serial]
 async fn test_scanner_compensates_existing_objects_across_write_paths() -> TestResult {
    init_logging();
    let source_bucket = "scanner-comp-src";
@@ -8352,7 +8284,6 @@ async fn test_scanner_compensates_existing_objects_across_write_paths() -> TestR
 /// written after the rule replicate normally (the setting only gates the
 /// existing-object resync path).
 #[tokio::test]
-#[serial]
 async fn test_scanner_never_compensates_when_existing_object_replication_disabled() -> TestResult {
    init_logging();
    let source_bucket = "scanner-disabled-src";
@@ -273,6 +273,7 @@ proptest = "1"
 rcgen.workspace = true
 insta = { workspace = true, features = ["yaml", "json"] }
 rustfs-crypto = { workspace = true }
+tonic-prost = { workspace = true }

 [build-dependencies]
 shadow-rs = { workspace = true, default-features = false, features = ["build", "metadata"] }
@@ -131,16 +131,19 @@ pub mod bucket {
    }

    pub mod metadata_sys {
+        #[cfg(feature = "test-util")]
+        pub use crate::bucket::metadata_sys::ConfigWriteLockProbe;
        pub use crate::bucket::metadata_sys::{
            BucketMetadataMutationGuard, BucketMetadataSys, ObjectLockConfigState, acquire_bucket_metadata_transaction_lock,
-            capture_bucket_metadata_incarnation, delete, delete_if_incarnation, get, get_accelerate_config, get_bucket_policy,
+            acquire_bucket_metadata_transaction_lock_for_incarnation, capture_bucket_metadata_incarnation, delete,
+            delete_if_incarnation, delete_under_transaction_lock, get, get_accelerate_config, get_bucket_policy,
            get_bucket_policy_raw, get_bucket_targets_config, get_config_from_disk, get_cors_config, get_durability_config,
            get_global_bucket_metadata_sys, get_lifecycle_config, get_logging_config, get_notification_config,
            get_object_lock_config, get_object_lock_config_state, get_public_access_block_config, get_quota_config,
            get_replication_config, get_request_payment_config, get_sse_config, get_tagging_config, get_versioning_config,
            get_website_config, init_bucket_metadata_sys, list_bucket_targets, reload_bucket_metadata, remove_bucket_metadata,
            set_bucket_metadata, update, update_bucket_targets_under_transaction_lock, update_config_with, update_if_incarnation,
-            update_under_transaction_lock,
+            update_quota_if_incarnation, update_under_transaction_lock,
        };
    }

@@ -182,17 +185,18 @@ pub mod bucket {
            mrf_backlog_observability_snapshot,
        };
        pub use crate::bucket::replication::{
-            BucketReplicationResyncStatus, BucketReplicationStats, BucketStats, DeleteReplicationConfigSnapshot,
-            DeletedObjectReplicationInfo, DurableMrfBacklog, DynReplicationPool, MrfOpKind, MrfReplicateEntry,
-            MustReplicateOptions, ObjectOpts, REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION, REMOTE_TARGET_UNSUPPORTED_FIELDS,
-            REMOTE_TARGET_WRITABLE_FIELDS, REPLICATE_INCOMING_DELETE, REPLICATION_CAPABILITY_CONTRACT_VERSION,
-            REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS, ReplicateDecision, ReplicateObjectInfo,
-            ReplicationBatchAdmission, ReplicationConfig, ReplicationConfigStructureError, ReplicationConfigurationExt,
-            ReplicationDeleteScheduleInput, ReplicationDeleteStateSource, ReplicationHealQueueResult, ReplicationObjectBridge,
-            ReplicationObjectIO, ReplicationOperation, ReplicationPoolTrait, ReplicationPriority, ReplicationQueueAdmission,
-            ReplicationScannerBridge, ReplicationState, ReplicationStats, ReplicationStatusType, ReplicationStorage,
-            ReplicationTargetValidationError, ReplicationType, ResyncOpts, ResyncStatusType, RuntimeReplicationTargetBacklog,
-            TargetReplicationResyncStatus, VersionPurgeStatusType, commit_force_delete_intent, complete_force_delete_intent,
+            BucketReplicationResyncStatus, BucketReplicationStat, BucketReplicationStats, BucketStats,
+            DeleteReplicationConfigSnapshot, DeletedObjectReplicationInfo, DurableMrfBacklog, DynReplicationPool, InQueueMetric,
+            MrfOpKind, MrfReplicateEntry, MustReplicateOptions, ObjectOpts, REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION,
+            REMOTE_TARGET_UNSUPPORTED_FIELDS, REMOTE_TARGET_WRITABLE_FIELDS, REPLICATE_INCOMING_DELETE,
+            REPLICATION_CAPABILITY_CONTRACT_VERSION, REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS,
+            ReplicateDecision, ReplicateObjectInfo, ReplicationBatchAdmission, ReplicationConfig,
+            ReplicationConfigStructureError, ReplicationConfigurationExt, ReplicationDeleteScheduleInput,
+            ReplicationDeleteStateSource, ReplicationHealQueueResult, ReplicationObjectBridge, ReplicationObjectIO,
+            ReplicationOperation, ReplicationPoolTrait, ReplicationPriority, ReplicationQueueAdmission, ReplicationScannerBridge,
+            ReplicationState, ReplicationStats, ReplicationStatusType, ReplicationStorage, ReplicationTargetValidationError,
+            ReplicationType, ResyncOpts, ResyncStatusType, RuntimeReplicationTargetBacklog, TargetReplicationResyncStatus,
+            VersionPurgeStatusType, XferStats, commit_force_delete_intent, complete_force_delete_intent,
            delete_replication_state_from_config, delete_replication_version_id, get_global_replication_pool,
            get_global_replication_stats, init_background_replication, invalid_replication_config_status_field,
            persist_force_delete_intent, read_durable_mrf_backlog, replication_state_to_filemeta, replication_status_to_filemeta,
@@ -276,7 +280,9 @@ pub mod cluster {
 }

 pub mod compression {
-    pub use crate::io_support::compress::{MIN_DISK_COMPRESSIBLE_SIZE, is_disk_compressible, is_disk_compression_enabled};
+    pub use crate::io_support::compress::{
+        MIN_DISK_COMPRESSIBLE_SIZE, is_disk_compressible, is_disk_compression_enabled, is_multipart_disk_compression_enabled,
+    };
 }

 pub mod config {
@@ -316,7 +322,7 @@ pub mod data_usage {
        DATA_USAGE_CACHE_NAME, apply_bucket_usage_memory_overlay, compute_bucket_usage,
        init_compression_total_memory_from_backend, invalidate_admin_data_usage_snapshot_cache,
        invalidate_data_usage_snapshot_cache, live_bucket_usage_computations, load_admin_data_usage_from_backend_cached,
-        load_compression_total_from_memory, load_data_usage_from_backend, load_data_usage_from_backend_cached,
+        load_compression_total_from_memory, load_data_usage_from_backend, load_data_usage_from_backend_cached, quota_object_size,
        record_bucket_delete_marker_memory, record_bucket_object_delete_memory, record_bucket_object_version_write_memory,
        record_bucket_object_write_memory, record_bucket_object_write_unknown_previous_memory, record_compression_total_memory,
        refresh_bucket_usage_from_object_layer, refresh_versioned_bucket_usage_from_object_layer,
@@ -367,14 +373,14 @@ pub mod error {

 pub mod erasure {
    pub use crate::erasure::coding::{
-        BitrotReader, BitrotWriter, BitrotWriterWrapper, CustomWriter, Erasure, ErasureConstructionError, ReedSolomonEncoder,
-        calc_shard_size, calc_shard_size_legacy,
+        BitrotReader, BitrotSelfTestError, BitrotWriter, BitrotWriterWrapper, CustomWriter, Erasure, ErasureConstructionError,
+        ReedSolomonEncoder, bitrot_self_test, calc_shard_size, calc_shard_size_legacy,
    };
 }

 pub mod event {
    pub use crate::event::name::EventName;
-    pub use crate::services::event_notification::{EventArgs, register_event_dispatch_hook};
+    pub use crate::services::event_notification::{EventArgs, register_event_dispatch_hook, send_event};
 }

 pub mod global {
@@ -403,8 +409,11 @@ pub mod metrics {
 }

 pub mod notification {
+    #[cfg(any(test, feature = "test-util"))]
+    pub use crate::services::notification_sys::rotate_cross_pool_fence_fleet_proof_for_test;
    pub use crate::services::notification_sys::{
-        NotificationPeerErr, NotificationSys, get_global_notification_sys, new_global_notification_sys,
+        CrossPoolFenceFleetProofToken, NotificationPeerErr, NotificationSys, acquire_cross_pool_fence_fleet_proof,
+        cross_pool_fence_fleet_proof_matches, get_global_notification_sys, new_global_notification_sys,
        start_remote_version_state_fleet_probe,
    };
 }
@@ -464,7 +473,8 @@ pub mod set_disk {

    #[cfg(feature = "test-util")]
    pub mod test_util {
-        pub use crate::set_disk::{PutObjectCommitBarrier, PutObjectCommitPause};
+        pub use crate::bucket::quota::reservation::fail_next_quota_ledger_save_for_test;
+        pub use crate::set_disk::{MultipartCommitBarrier, MultipartCommitPause, PutObjectCommitBarrier, PutObjectCommitPause};
    }
 }

@@ -473,6 +483,7 @@ pub mod store_list {
 }

 pub mod storage {
+    pub use crate::core::pools::HealLifecycleExpiryContext;
    pub use crate::store::HealWalkVersion;
    pub use crate::store::{
        ECStore, all_local_disk, all_local_disk_path, find_local_disk_by_ref, init_local_disks,
@@ -58,7 +58,9 @@ use rustfs_utils::http::{
 };
 use rustfs_utils::http::{
    SUFFIX_FORCE_DELETE, SUFFIX_SOURCE_DELETEMARKER, SUFFIX_SOURCE_ETAG, SUFFIX_SOURCE_MTIME, SUFFIX_SOURCE_REPLICATION_CHECK,
-    SUFFIX_SOURCE_REPLICATION_REQUEST, SUFFIX_SOURCE_VERSION_ID, insert_header,
+    SUFFIX_SOURCE_REPLICATION_LEGALHOLD_TIMESTAMP, SUFFIX_SOURCE_REPLICATION_REQUEST,
+    SUFFIX_SOURCE_REPLICATION_RETENTION_TIMESTAMP, SUFFIX_SOURCE_REPLICATION_TAGGING_TIMESTAMP, SUFFIX_SOURCE_VERSION_ID,
+    insert_header,
 };
 use rustls_pki_types::pem::PemObject;
 use serde::{Deserialize, Serialize};
@@ -80,7 +82,6 @@ use tracing::warn;
 use url::Url;
 use uuid::Uuid;

-const DEFAULT_HEALTH_CHECK_RELOAD_DURATION: Duration = Duration::from_secs(30 * 60);
 const MAX_CONCURRENT_TARGET_HEALTH_CHECKS: usize = 16;
 const REDACTED_CREDENTIAL: &str = "<redacted>";

@@ -1476,9 +1477,12 @@ impl Default for AdvancedPutOptions {
            replication_status: ReplicationStatusType::Pending,
            source_mtime: OffsetDateTime::now_utc(),
            replication_request: false,
-            retention_timestamp: OffsetDateTime::now_utc(),
-            tagging_timestamp: OffsetDateTime::now_utc(),
-            legalhold_timestamp: OffsetDateTime::now_utc(),
+            // UNIX_EPOCH means "never modified": header() must not emit a
+            // timestamp header for it, otherwise a receiver would treat an
+            // unset category as a modification made right now.
+            retention_timestamp: OffsetDateTime::UNIX_EPOCH,
+            tagging_timestamp: OffsetDateTime::UNIX_EPOCH,
+            legalhold_timestamp: OffsetDateTime::UNIX_EPOCH,
            replication_validity_check: false,
        }
    }
@@ -1545,8 +1549,8 @@ impl Default for PutObjectOptions {
    }
 }

-#[allow(dead_code)]
 impl PutObjectOptions {
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn set_match_etag(&mut self, etag: &str) {
        if etag == "*" {
            self.custom_header
@@ -1557,6 +1561,7 @@ impl PutObjectOptions {
        }
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn set_match_etag_except(&mut self, etag: &str) {
        if etag == "*" {
            self.custom_header
@@ -1675,6 +1680,16 @@ impl PutObjectOptions {
            );
        }

+        for (suffix, timestamp) in [
+            (SUFFIX_SOURCE_REPLICATION_TAGGING_TIMESTAMP, self.internal.tagging_timestamp),
+            (SUFFIX_SOURCE_REPLICATION_RETENTION_TIMESTAMP, self.internal.retention_timestamp),
+            (SUFFIX_SOURCE_REPLICATION_LEGALHOLD_TIMESTAMP, self.internal.legalhold_timestamp),
+        ] {
+            if timestamp.unix_timestamp() != 0 {
+                insert_header(&mut header, suffix, timestamp.format(&Rfc3339).unwrap_or_default());
+            }
+        }
+
        if self.internal.replication_request {
            insert_header(&mut header, SUFFIX_SOURCE_REPLICATION_REQUEST, "true");
        }
@@ -1682,6 +1697,7 @@ impl PutObjectOptions {
        header
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn validate(&self, _c: Arc<TargetClient>) -> Result<(), std::io::Error> {
        //if self.checksum.is_set() {
        /*if !self.trailing_header_support {
@@ -2842,6 +2858,57 @@ mod tests {
        );
    }

+    #[test]
+    fn put_object_headers_carry_replication_timestamp_headers() {
+        // MinIO receivers resolve concurrent tag/retention/legal-hold edits by
+        // last-writer-wins on these headers (object-api-options.go parses them
+        // as RFC3339); a replica without them loses every conflict resolution.
+        let mut opts = PutObjectOptions::default();
+        opts.internal.replication_request = true;
+        let tagging = OffsetDateTime::from_unix_timestamp(1_700_000_001).expect("valid timestamp");
+        let retention = OffsetDateTime::from_unix_timestamp(1_700_000_002).expect("valid timestamp");
+        let legalhold = OffsetDateTime::from_unix_timestamp(1_700_000_003).expect("valid timestamp");
+        opts.internal.tagging_timestamp = tagging;
+        opts.internal.retention_timestamp = retention;
+        opts.internal.legalhold_timestamp = legalhold;
+
+        let header = opts.header();
+        for (suffix, expected) in [
+            ("source-replication-tagging-timestamp", tagging),
+            ("source-replication-retention-timestamp", retention),
+            ("source-replication-legalhold-timestamp", legalhold),
+        ] {
+            assert_eq!(
+                rustfs_utils::http::get_header(&header, suffix).as_deref(),
+                Some(expected.format(&Rfc3339).expect("RFC3339 timestamp").as_str()),
+                "replication put requests must carry the {suffix} header"
+            );
+        }
+    }
+
+    #[test]
+    fn put_object_headers_omit_unset_replication_timestamps() {
+        // UNIX_EPOCH means "never modified on the source"; sending it would
+        // make the receiver treat an unset category as a fresh modification.
+        let mut opts = PutObjectOptions::default();
+        opts.internal.replication_request = true;
+        opts.internal.tagging_timestamp = OffsetDateTime::UNIX_EPOCH;
+        opts.internal.retention_timestamp = OffsetDateTime::UNIX_EPOCH;
+        opts.internal.legalhold_timestamp = OffsetDateTime::UNIX_EPOCH;
+
+        let header = opts.header();
+        for suffix in [
+            "source-replication-tagging-timestamp",
+            "source-replication-retention-timestamp",
+            "source-replication-legalhold-timestamp",
+        ] {
+            assert!(
+                rustfs_utils::http::get_header(&header, suffix).is_none(),
+                "unset {suffix} must not be sent to replication targets"
+            );
+        }
+    }
+
    #[tokio::test]
    async fn get_remote_target_client_internal_rejects_loopback_endpoint() {
        let sys = BucketTargetSys::default();
@@ -46,15 +46,13 @@ use crate::bucket::lifecycle::transition_transaction::run_transition_transaction
 use crate::bucket::object_lock::ObjectLockApi;
 use crate::bucket::versioning::VersioningApi as _;
 use crate::bucket::versioning_sys::BucketVersioningSys;
-use crate::client::object_api_utils::new_getobjectreader;
 use crate::disk::error::DiskError;
 use crate::disk::{DeleteOptions, Disk, DiskAPI, RUSTFS_META_BUCKET, RUSTFS_META_MULTIPART_BUCKET, STORAGE_FORMAT_FILE};
 use crate::error::Error;
 use crate::error::StorageError;
-use crate::error::{
-    error_resp_to_object_err, is_err_object_not_found, is_err_read_quorum, is_err_version_not_found, is_network_or_host_down,
-};
+use crate::error::{is_err_object_not_found, is_err_read_quorum, is_err_version_not_found, is_network_or_host_down};
 use crate::object_api::{GetObjectReader, ObjectInfo, ObjectOptions};
+use crate::object_api::{ObjectEncryptionResolver, ReadPlan};
 use crate::services::tier::{
    tier::{TierConfigMgr, TierOperationLease, tier_destination_id_from_metadata},
    warm_backend::WarmBackendGetOpts,
@@ -128,11 +126,23 @@ const EVENT_LIFECYCLE_EXPIRED_DETECTED: &str = "lifecycle_expired_detected";
 const EVENT_LIFECYCLE_NOT_ENQUEUED: &str = "lifecycle_not_enqueued";
 const EVENT_LIFECYCLE_DELETE_DISPATCHED: &str = "lifecycle_delete_dispatched";
 const EVENT_LIFECYCLE_DELETE_COMPLETED: &str = "lifecycle_delete_completed";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 const EVENT_LIFECYCLE_TIER_AUDIT: &str = "lifecycle_tier_audit";
 const EVENT_LIFECYCLE_TIER_OPERATION_FAILED: &str = "lifecycle_tier_operation_failed";
 const EVENT_LIFECYCLE_DELETE_FAILED: &str = "lifecycle_delete_failed";

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub type TimeFn = Arc<dyn Fn() -> Pin<Box<dyn Future<Output = ()> + Send>> + Send + Sync + 'static>;
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub type TraceFn =
    Arc<dyn Fn(String, HashMap<String, String>) -> Pin<Box<dyn Future<Output = ()> + Send>> + Send + Sync + 'static>;
 pub type ExpiryOpType = Box<dyn ExpiryOp + Send + Sync + 'static>;
@@ -142,9 +152,21 @@ static TIER_FREE_VERSION_RECOVERY_STARTED: OnceLock<()> = OnceLock::new();
 static MANUAL_TRANSITION_JOB_RECOVERY_STARTED: OnceLock<()> = OnceLock::new();

 pub const AMZ_OBJECT_TAGGING: &str = "X-Amz-Tagging";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_TAG_COUNT: &str = "x-amz-tagging-count";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_TAG_DIRECTIVE: &str = "X-Amz-Tagging-Directive";
 pub const AMZ_ENCRYPTION_AES: &str = "AES256";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_ENCRYPTION_KMS: &str = "aws:kms";

 pub const ERR_INVALID_STORAGECLASS: &str = "invalid tier.";
@@ -282,6 +304,10 @@ impl LifecycleSys {
        }
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
    pub fn trace(oi: &ObjectInfo) -> TraceFn {
        let bucket = oi.bucket.clone();
        let name = oi.name.clone();
@@ -430,16 +456,23 @@ impl<'a> LifecycleExpiryTrace<'a> {
    }
 }

-#[allow(dead_code)]
 impl ExpiryStats {
    pub fn missed_tasks(&self) -> i64 {
        self.missed_expiry_tasks.load(Ordering::SeqCst)
    }

+    #[allow(
+        dead_code,
+        reason = "asserted by this file's tests; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
    fn missed_free_vers_tasks(&self) -> i64 {
        self.missed_freevers_tasks.load(Ordering::SeqCst)
    }

+    #[allow(
+        dead_code,
+        reason = "asserted by this file's tests; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
    fn missed_tier_journal_tasks(&self) -> i64 {
        self.missed_tier_journal_tasks.load(Ordering::SeqCst)
    }
@@ -572,6 +605,10 @@ async fn delete_free_version_remote_object(
    Ok(())
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_free_version_remote_object_then<T, F, Fut>(
    oi: &ObjectInfo,
    tier_config_mgr: &Arc<RwLock<TierConfigMgr>>,
@@ -1746,7 +1783,7 @@ impl TransitionState {
                                .await;
                            }
                            global_metrics().record_scanner_transition_failed(1);
-                            if !is_err_version_not_found(&err) && !is_err_object_not_found(&err) && !is_network_or_host_down(&err.to_string(), false) && !err.to_string().contains("use of closed network connection") {
+                            if !is_err_version_not_found(&err) && !is_err_object_not_found(&err) && !is_network_or_host_down(&err.to_string(), false) {
                                error!(
                                    event = EVENT_LIFECYCLE_TIER_OPERATION_FAILED,
                                    component = LOG_COMPONENT_ECSTORE,
@@ -2870,12 +2907,37 @@ fn stale_upload_default_due(initiated: OffsetDateTime, default_expiry: StdDurati
    initiated + time::Duration::seconds(default_expiry.as_secs() as i64)
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn stale_upload_current_size(set: &Arc<SetDisks>, metadata: &HashMap<String, String>, upload_dir: &str) -> Option<usize> {
+    stale_upload_current_size_with_opts(set, metadata, upload_dir, false).await
+}
+
+async fn stale_upload_current_size_with_opts(
+    set: &Arc<SetDisks>,
+    metadata: &HashMap<String, String>,
+    upload_dir: &str,
+    no_lock: bool,
+) -> Option<usize> {
    let bucket = metadata.get(RUSTFS_MULTIPART_BUCKET_KEY)?;
    let object = metadata.get(RUSTFS_MULTIPART_OBJECT_KEY)?;
    let upload_id = encode_stale_upload_id(upload_dir);
+    let data_movement = rustfs_utils::http::contains_key_str(metadata, rustfs_utils::http::SUFFIX_DATA_MOVEMENT_UPLOAD);
    let parts = set
-        .list_object_parts(bucket, object, &upload_id, None, MAX_PARTS_COUNT, &ObjectOptions::default())
+        .list_object_parts(
+            bucket,
+            object,
+            &upload_id,
+            None,
+            MAX_PARTS_COUNT,
+            &ObjectOptions {
+                data_movement,
+                no_lock,
+                ..Default::default()
+            },
+        )
        .await
        .ok()?;

@@ -2893,7 +2955,12 @@ async fn stale_upload_lifecycle_due(
    metadata: &HashMap<String, String>,
    initiated: OffsetDateTime,
    upload_dir: &str,
+    no_lock: bool,
 ) -> Option<OffsetDateTime> {
+    if rustfs_utils::http::contains_key_str(metadata, rustfs_utils::http::SUFFIX_DATA_MOVEMENT_UPLOAD) {
+        return None;
+    }
+
    let bucket = metadata.get(RUSTFS_MULTIPART_BUCKET_KEY)?;
    let object = metadata.get(RUSTFS_MULTIPART_OBJECT_KEY)?;

@@ -2906,7 +2973,9 @@ async fn stale_upload_lifecycle_due(
        name: object.clone(),
        user_tags: metadata.get(AMZ_OBJECT_TAGGING).cloned().unwrap_or_default(),
        mod_time: Some(initiated),
-        size: stale_upload_current_size(set, metadata, upload_dir).await.unwrap_or_default(),
+        size: stale_upload_current_size_with_opts(set, metadata, upload_dir, no_lock)
+            .await
+            .unwrap_or_default(),
        is_latest: true,
        delete_marker: false,
        user_defined: metadata.clone(),
@@ -2934,6 +3003,7 @@ async fn read_stale_multipart_candidate(
        FileInfoOpts {
            data: false,
            include_free_versions: false,
+            include_part_checksums: false,
        },
    ) {
        Ok(file_info) => (Some(file_info.metadata), file_info.mod_time),
@@ -2973,36 +3043,30 @@ fn merge_stale_multipart_candidate(
    }
 }

+fn is_multipart_sha_dir(path: &str) -> bool {
+    path.len() == 64 && path.bytes().all(|byte| byte.is_ascii_hexdigit())
+}
+
+fn multipart_sha_path(root: &str, entry: &str) -> Option<String> {
+    let sha_dir = entry.trim_end_matches('/');
+    is_multipart_sha_dir(sha_dir).then(|| {
+        if root.is_empty() {
+            sha_dir.to_string()
+        } else {
+            format!("{root}/{sha_dir}")
+        }
+    })
+}
+
 async fn cleanup_empty_multipart_sha_dirs_on_local_disks(set: &Arc<SetDisks>) {
    for disk in set.get_local_disks().await.into_iter().flatten() {
        if !disk.is_online().await {
            continue;
        }

-        let sha_dirs = match disk
-            .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, "", -1)
-            .await
-        {
-            Ok(entries) => entries,
-            Err(err) => {
-                if err != DiskError::FileNotFound && err != DiskError::VolumeNotFound {
-                    debug!(
-                        event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
-                        component = LOG_COMPONENT_ECSTORE,
-                        subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                        error = ?err,
-                        reason = "multipart_root_list_failed",
-                        "Skipped empty multipart sha cleanup"
-                    );
-                }
-                continue;
-            }
-        };
-
-        for sha_dir in sha_dirs {
-            let sha_dir = sha_dir.trim_end_matches('/').to_string();
-            let upload_dirs = match disk
-                .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, &sha_dir, -1)
+        for root in ["", crate::set_disk::DATA_MOVEMENT_MULTIPART_PREFIX] {
+            let sha_dirs = match disk
+                .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, root, -1)
                .await
            {
                Ok(entries) => entries,
@@ -3012,9 +3076,8 @@ async fn cleanup_empty_multipart_sha_dirs_on_local_disks(set: &Arc<SetDisks>) {
                            event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
                            component = LOG_COMPONENT_ECSTORE,
                            subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                            sha_dir = %sha_dir,
                            error = ?err,
-                            reason = "multipart_sha_dir_list_failed",
+                            reason = "multipart_root_list_failed",
                            "Skipped empty multipart sha cleanup"
                        );
                    }
@@ -3022,25 +3085,48 @@ async fn cleanup_empty_multipart_sha_dirs_on_local_disks(set: &Arc<SetDisks>) {
                }
            };

-            if !upload_dirs.is_empty() {
-                continue;
-            }
+            for sha_dir in sha_dirs.into_iter().filter_map(|entry| multipart_sha_path(root, &entry)) {
+                let upload_dirs = match disk
+                    .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, &sha_dir, -1)
+                    .await
+                {
+                    Ok(entries) => entries,
+                    Err(err) => {
+                        if err != DiskError::FileNotFound && err != DiskError::VolumeNotFound {
+                            debug!(
+                                event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
+                                component = LOG_COMPONENT_ECSTORE,
+                                subsystem = LOG_SUBSYSTEM_LIFECYCLE,
+                                sha_dir = %sha_dir,
+                                error = ?err,
+                                reason = "multipart_sha_dir_list_failed",
+                                "Skipped empty multipart sha cleanup"
+                            );
+                        }
+                        continue;
+                    }
+                };

-            if let Err(err) = disk
-                .delete(RUSTFS_META_MULTIPART_BUCKET, &sha_dir, DeleteOptions::default())
-                .await
-                && err != DiskError::FileNotFound
-                && err != DiskError::VolumeNotFound
-            {
-                debug!(
-                    event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
-                    component = LOG_COMPONENT_ECSTORE,
-                    subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                    sha_dir = %sha_dir,
-                    error = ?err,
-                    reason = "multipart_sha_dir_remove_failed",
-                    "Failed to remove empty multipart sha dir"
-                );
+                if !upload_dirs.is_empty() {
+                    continue;
+                }
+
+                if let Err(err) = disk
+                    .delete(RUSTFS_META_MULTIPART_BUCKET, &sha_dir, DeleteOptions::default())
+                    .await
+                    && err != DiskError::FileNotFound
+                    && err != DiskError::VolumeNotFound
+                {
+                    debug!(
+                        event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
+                        component = LOG_COMPONENT_ECSTORE,
+                        subsystem = LOG_SUBSYSTEM_LIFECYCLE,
+                        sha_dir = %sha_dir,
+                        error = ?err,
+                        reason = "multipart_sha_dir_remove_failed",
+                        "Failed to remove empty multipart sha dir"
+                    );
+                }
            }
        }
    }
@@ -3058,30 +3144,9 @@ async fn cleanup_stale_multipart_uploads_in_set(set: &Arc<SetDisks>, now: Offset
            continue;
        }

-        let sha_dirs = match disk
-            .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, "", -1)
-            .await
-        {
-            Ok(entries) => entries,
-            Err(err) => {
-                if err != DiskError::FileNotFound && err != DiskError::VolumeNotFound {
-                    debug!(
-                        event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
-                        component = LOG_COMPONENT_ECSTORE,
-                        subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                        error = ?err,
-                        reason = "multipart_root_list_failed",
-                        "Skipped stale multipart cleanup"
-                    );
-                }
-                continue;
-            }
-        };
-
-        for sha_dir in sha_dirs {
-            let sha_dir = sha_dir.trim_end_matches('/').to_string();
-            let upload_dirs = match disk
-                .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, &sha_dir, -1)
+        for root in ["", crate::set_disk::DATA_MOVEMENT_MULTIPART_PREFIX] {
+            let sha_dirs = match disk
+                .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, root, -1)
                .await
            {
                Ok(entries) => entries,
@@ -3091,9 +3156,8 @@ async fn cleanup_stale_multipart_uploads_in_set(set: &Arc<SetDisks>, now: Offset
                            event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
                            component = LOG_COMPONENT_ECSTORE,
                            subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                            sha_dir = %sha_dir,
                            error = ?err,
-                            reason = "multipart_sha_dir_list_failed",
+                            reason = "multipart_root_list_failed",
                            "Skipped stale multipart cleanup"
                        );
                    }
@@ -3101,39 +3165,62 @@ async fn cleanup_stale_multipart_uploads_in_set(set: &Arc<SetDisks>, now: Offset
                }
            };

-            for upload_dir in upload_dirs {
-                let upload_dir = upload_dir.trim_end_matches('/').to_string();
-                let candidate_path = format!("{sha_dir}/{upload_dir}");
-                if candidates
-                    .get(&candidate_path)
-                    .is_some_and(|existing: &StaleMultipartUploadCandidate| existing.metadata.is_some())
+            for sha_dir in sha_dirs.into_iter().filter_map(|entry| multipart_sha_path(root, &entry)) {
+                let upload_dirs = match disk
+                    .list_dir(RUSTFS_META_MULTIPART_BUCKET, RUSTFS_META_MULTIPART_BUCKET, &sha_dir, -1)
+                    .await
                {
-                    continue;
-                }
-
-                let candidate = match read_stale_multipart_candidate(disk.as_ref(), &sha_dir, &upload_dir).await {
-                    Ok(candidate) => candidate,
+                    Ok(entries) => entries,
                    Err(err) => {
-                        if err != DiskError::FileNotFound {
+                        if err != DiskError::FileNotFound && err != DiskError::VolumeNotFound {
                            debug!(
                                event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
                                component = LOG_COMPONENT_ECSTORE,
                                subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                                path = %candidate_path,
+                                sha_dir = %sha_dir,
                                error = ?err,
-                                reason = "multipart_metadata_read_failed",
-                                "Multipart metadata unavailable during stale cleanup"
+                                reason = "multipart_sha_dir_list_failed",
+                                "Skipped stale multipart cleanup"
                            );
                        }
-                        let initiated = initiated_from_upload_dir(&upload_dir, None);
-                        StaleMultipartUploadCandidate {
-                            path: candidate_path,
-                            initiated,
-                            metadata: None,
-                        }
+                        continue;
                    }
                };
-                merge_stale_multipart_candidate(&mut candidates, candidate);
+
+                for upload_dir in upload_dirs {
+                    let upload_dir = upload_dir.trim_end_matches('/').to_string();
+                    let candidate_path = format!("{sha_dir}/{upload_dir}");
+                    if candidates
+                        .get(&candidate_path)
+                        .is_some_and(|existing: &StaleMultipartUploadCandidate| existing.metadata.is_some())
+                    {
+                        continue;
+                    }
+
+                    let candidate = match read_stale_multipart_candidate(disk.as_ref(), &sha_dir, &upload_dir).await {
+                        Ok(candidate) => candidate,
+                        Err(err) => {
+                            if err != DiskError::FileNotFound {
+                                debug!(
+                                    event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
+                                    component = LOG_COMPONENT_ECSTORE,
+                                    subsystem = LOG_SUBSYSTEM_LIFECYCLE,
+                                    path = %candidate_path,
+                                    error = ?err,
+                                    reason = "multipart_metadata_read_failed",
+                                    "Multipart metadata unavailable during stale cleanup"
+                                );
+                            }
+                            let initiated = initiated_from_upload_dir(&upload_dir, None);
+                            StaleMultipartUploadCandidate {
+                                path: candidate_path,
+                                initiated,
+                                metadata: None,
+                            }
+                        }
+                    };
+                    merge_stale_multipart_candidate(&mut candidates, candidate);
+                }
            }
        }
    }
@@ -3142,7 +3229,7 @@ async fn cleanup_stale_multipart_uploads_in_set(set: &Arc<SetDisks>, now: Offset
        let upload_dir = candidate.path.rsplit('/').next().unwrap_or_default().to_string();
        let mut due = stale_upload_default_due(candidate.initiated, default_expiry);
        if let Some(metadata) = candidate.metadata.as_ref()
-            && let Some(lifecycle_due) = stale_upload_lifecycle_due(set, metadata, candidate.initiated, &upload_dir).await
+            && let Some(lifecycle_due) = stale_upload_lifecycle_due(set, metadata, candidate.initiated, &upload_dir, false).await
            && lifecycle_due < due
        {
            due = lifecycle_due;
@@ -3152,34 +3239,49 @@ async fn cleanup_stale_multipart_uploads_in_set(set: &Arc<SetDisks>, now: Offset
            continue;
        }

-        match set.delete_all(RUSTFS_META_MULTIPART_BUCKET, &candidate.path).await {
+        let cleanup_guard = match set.lock_stale_multipart_cleanup(&candidate.path).await {
+            Ok(guard) => guard,
+            Err(err) => {
+                debug!(
+                    event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
+                    component = LOG_COMPONENT_ECSTORE,
+                    subsystem = LOG_SUBSYSTEM_LIFECYCLE,
+                    path = %candidate.path,
+                    error = ?err,
+                    reason = "multipart_cleanup_lock_or_recheck_failed",
+                    "Skipped stale multipart cleanup"
+                );
+                continue;
+            }
+        };
+        let current_metadata = cleanup_guard.file_info().metadata.clone();
+        let current_initiated = initiated_from_upload_dir(&upload_dir, cleanup_guard.file_info().mod_time);
+        let mut current_due = stale_upload_default_due(current_initiated, default_expiry);
+        if let Some(lifecycle_due) =
+            stale_upload_lifecycle_due(set, &current_metadata, current_initiated, &upload_dir, true).await
+            && lifecycle_due < current_due
+        {
+            current_due = lifecycle_due;
+        }
+        if now < current_due || cleanup_guard.is_lock_lost() {
+            continue;
+        }
+
+        match cleanup_guard.delete(set).await {
            Ok(()) => {
                deleted += 1;
                let upload_id = encode_stale_upload_id(&upload_dir);
-                if let Some(metadata) = candidate.metadata.as_ref() {
-                    debug!(
-                        bucket = metadata.get(RUSTFS_MULTIPART_BUCKET_KEY).cloned().unwrap_or_default(),
-                        object = metadata.get(RUSTFS_MULTIPART_OBJECT_KEY).cloned().unwrap_or_default(),
-                        upload_id = %upload_id,
-                        due = ?due,
-                        event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
-                        component = LOG_COMPONENT_ECSTORE,
-                        subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                        state = "removed",
-                        "Removed stale multipart upload"
-                    );
-                } else {
-                    debug!(
-                        path = %candidate.path,
-                        upload_id = %upload_id,
-                        due = ?due,
-                        event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
-                        component = LOG_COMPONENT_ECSTORE,
-                        subsystem = LOG_SUBSYSTEM_LIFECYCLE,
-                        state = "removed",
-                        "Removed stale multipart upload"
-                    );
-                }
+                debug!(
+                    bucket = current_metadata.get(RUSTFS_MULTIPART_BUCKET_KEY).cloned().unwrap_or_default(),
+                    object = current_metadata.get(RUSTFS_MULTIPART_OBJECT_KEY).cloned().unwrap_or_default(),
+                    upload_id = %upload_id,
+                    due = ?current_due,
+                    event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
+                    component = LOG_COMPONENT_ECSTORE,
+                    subsystem = LOG_SUBSYSTEM_LIFECYCLE,
+                    state = "removed",
+                    "Removed stale multipart upload"
+                );
            }
            Err(err) => debug!(
                event = EVENT_LIFECYCLE_STALE_MULTIPART_CLEANUP,
@@ -3293,6 +3395,10 @@ pub async fn validate_transition_tier(lc: &BucketLifecycleConfiguration) -> Resu
    Ok(())
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 fn mark_delete_opts_skip_decommissioned_on_remote_success(opts: &mut ObjectOptions, remote_delete_succeeded: bool) {
    if remote_delete_succeeded {
        opts.skip_decommissioned = true;
@@ -4280,6 +4386,10 @@ pub async fn expire_transitioned_object(
    Ok(dobj)
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub fn gen_transition_objname(bucket: &str) -> Result<String, Error> {
    let us = Uuid::new_v4().to_string();
    let mut hasher = Sha256::new();
@@ -4314,6 +4424,10 @@ pub async fn transition_object(api: Arc<ECStore>, oi: &ObjectInfo, lae: LcAuditE
    result
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub fn audit_tier_actions(_tier: &str, bytes: i64) -> TimeFn {
    let tier = _tier.to_string();
    Arc::new(move || {
@@ -4332,6 +4446,10 @@ pub fn audit_tier_actions(_tier: &str, bytes: i64) -> TimeFn {
    })
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn get_transitioned_object_reader(
    bucket: &str,
    object: &str,
@@ -4339,9 +4457,10 @@ pub async fn get_transitioned_object_reader(
    h: &HeaderMap,
    oi: &ObjectInfo,
    opts: &ObjectOptions,
+    resolver: Option<&dyn ObjectEncryptionResolver>,
 ) -> Result<GetObjectReader, std::io::Error> {
    let tier_config_mgr = runtime_sources::tier_config_mgr_handle();
-    get_transitioned_object_reader_with_tier_manager(bucket, object, rs, h, oi, opts, &tier_config_mgr).await
+    get_transitioned_object_reader_with_tier_manager(bucket, object, rs, h, oi, opts, &tier_config_mgr, resolver).await
 }

 fn validate_transition_remote_version(oi: &ObjectInfo) -> Result<bool, std::io::Error> {
@@ -4361,6 +4480,10 @@ fn validate_transition_remote_version(oi: &ObjectInfo) -> Result<bool, std::io::
    }
 }

+// The resolver joins the tier manager as the second injected port this read
+// needs; grouping the request half into a struct would churn every call site of
+// a bug fix.
+#[allow(clippy::too_many_arguments)]
 pub(crate) async fn get_transitioned_object_reader_with_tier_manager(
    bucket: &str,
    object: &str,
@@ -4369,6 +4492,7 @@ pub(crate) async fn get_transitioned_object_reader_with_tier_manager(
    oi: &ObjectInfo,
    opts: &ObjectOptions,
    tier_config_mgr: &Arc<RwLock<TierConfigMgr>>,
+    resolver: Option<&dyn ObjectEncryptionResolver>,
 ) -> Result<GetObjectReader, std::io::Error> {
    validate_transition_remote_version(oi)?;
    let expected_identity = tier_destination_id_from_metadata(&oi.user_defined)?;
@@ -4386,11 +4510,16 @@ pub(crate) async fn get_transitioned_object_reader_with_tier_manager(

    tgt_client.validate_remote_version_id(&oi.transitioned_object.version_id)?;

-    let ret = new_getobjectreader(rs, oi, opts, h);
-    if let Err(err) = ret {
-        return Err(error_resp_to_object_err(err, vec![bucket, object]));
-    }
-    let (get_fn, off, length) = ret.expect("get_transitioned_object_reader should succeed after error check");
+    // The same read plan the local path uses, so the tier fetch is positioned in
+    // the object's *stored* coordinate system and the stream is handed the same
+    // decrypt/decompress transforms. Reading an encrypted object's ciphertext
+    // through a plaintext-coordinate range and skipping the transform is how a
+    // transitioned SSE object used to come back as silently corrupt bytes of the
+    // right length (rustfs/rustfs#6025).
+    let plan = ReadPlan::build_for_request(rs.clone(), oi, opts, h, resolver)
+        .await
+        .map_err(|err| std::io::Error::other(format!("building the read plan for {bucket}/{object} failed: {err}")))?;
+    let (off, length) = (plan.storage_offset() as i64, plan.storage_length());
    let mut gopts = WarmBackendGetOpts::default();

    if off >= 0 && length >= 0 {
@@ -4427,7 +4556,10 @@ pub(crate) async fn get_transitioned_object_reader_with_tier_manager(
            );
            e
        })?;
-    Ok(attach_tier_operation_lease(get_fn(reader, h.clone()), tgt_client))
+    let object_reader = plan
+        .into_object_reader(Box::new(reader), oi)
+        .map_err(|err| std::io::Error::other(format!("wrapping the tier stream for {bucket}/{object} failed: {err}")))?;
+    Ok(attach_tier_operation_lease(object_reader, tgt_client))
 }

 struct TierOperationLeaseReader {
@@ -5072,6 +5204,10 @@ async fn lifecycle_delete_config_snapshot(api: &ECStore, oi: &ObjectInfo) -> Res
    ReplicationObjectBridge::delete_request_config(api, &oi.bucket).await
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn apply_lifecycle_action(event: &lifecycle::Event, src: &LcEventSrc, oi: &ObjectInfo) -> bool {
    let mut success = false;
    match event.action {
@@ -5162,6 +5298,7 @@ mod tests {
    use crate::services::tier::tier::TierConfigMgr;
    #[cfg(feature = "test-util")]
    use crate::services::tier::warm_backend::WarmBackend as _;
+    use crate::set_disk::{MultipartCommitBarrier, MultipartCommitPause};
    use crate::set_disk::{RUSTFS_MULTIPART_BUCKET_KEY, RUSTFS_MULTIPART_OBJECT_KEY};
    use crate::storage_api_contracts::namespace::NamespaceLocking as _;
    use crate::storage_api_contracts::{
@@ -5714,6 +5851,7 @@ mod tests {
            &object_info,
            &ObjectOptions::default(),
            &manager,
+            None,
        )
        .await
        .expect("transitioned reader should open");
@@ -5778,6 +5916,7 @@ mod tests {
            &object_info,
            &ObjectOptions::default(),
            &manager,
+            None,
        )
        .await
        {
@@ -5818,6 +5957,7 @@ mod tests {
            &object_info,
            &ObjectOptions::default(),
            &manager,
+            None,
        )
        .await
        {
@@ -6055,6 +6195,7 @@ mod tests {
            &oi,
            &ObjectOptions::default(),
            &manager,
+            None,
        )
        .await
        {
@@ -6078,6 +6219,7 @@ mod tests {
            &oi,
            &ObjectOptions::default(),
            &manager,
+            None,
        )
        .await
        {
@@ -7343,6 +7485,10 @@ mod tests {
    // process environment while `env::set_var`/`env::remove_var` is active.
    // SAFETY: keep this note adjacent to the allowance for the repository guard.
    #[allow(unsafe_code)]
+    #[allow(
+        dead_code,
+        reason = "transition-queue env fixture kept for tests that scope those vars; no test uses it today (backlog#1823)"
+    )]
    async fn with_transition_queue_env_async<F, Fut>(capacity: Option<&str>, timeout_ms: Option<&str>, test_fn: F)
    where
        F: FnOnce() -> Fut,
@@ -11926,6 +12072,135 @@ mod tests {
        assert!(is_err_invalid_upload_id(&err));
    }

+    #[tokio::test]
+    #[serial]
+    async fn stale_multipart_cleanup_handles_data_movement_namespace() {
+        let (_paths, ecstore) = setup_test_env().await;
+        let bucket = format!("stale-data-movement-{}", Uuid::new_v4().simple());
+        create_test_bucket(&ecstore, &bucket).await;
+
+        let create_upload = |object: &'static str, mod_time| {
+            let ecstore = ecstore.clone();
+            let bucket = bucket.clone();
+            async move {
+                let mut metadata = HashMap::new();
+                rustfs_utils::http::insert_str(
+                    &mut metadata,
+                    rustfs_utils::http::SUFFIX_DATA_MOVEMENT_UPLOAD,
+                    "cleanup-test".to_string(),
+                );
+                ecstore
+                    .new_multipart_upload(
+                        &bucket,
+                        object,
+                        &ObjectOptions {
+                            data_movement: true,
+                            mod_time: Some(mod_time),
+                            user_defined: metadata,
+                            ..Default::default()
+                        },
+                    )
+                    .await
+                    .expect("data movement multipart upload should be created")
+                    .upload_id
+            }
+        };
+
+        let stale_object = "stale-internal.bin";
+        let active_object = "active-internal.bin";
+        let now = OffsetDateTime::now_utc();
+        let stale_upload_id = create_upload(stale_object, now - time::Duration::hours(30)).await;
+        let active_upload_id = create_upload(active_object, now).await;
+
+        let deleted = cleanup_stale_multipart_uploads_once_at(ecstore.clone(), now, StdDuration::from_secs(24 * 60 * 60)).await;
+        assert!(deleted >= 1, "expected stale data movement upload to be removed");
+
+        let internal_opts = ObjectOptions {
+            data_movement: true,
+            ..Default::default()
+        };
+        let stale_err = ecstore
+            .get_multipart_info(&bucket, stale_object, &stale_upload_id, &internal_opts)
+            .await
+            .expect_err("stale data movement upload should be removed");
+        assert!(is_err_invalid_upload_id(&stale_err));
+        ecstore
+            .get_multipart_info(&bucket, active_object, &active_upload_id, &internal_opts)
+            .await
+            .expect("active data movement upload should remain available");
+    }
+
+    #[tokio::test]
+    #[serial]
+    async fn stale_multipart_cleanup_waits_for_data_movement_part_commit() {
+        let (_paths, ecstore) = setup_test_env().await;
+        let bucket = format!("stale-data-movement-lock-{}", Uuid::new_v4().simple());
+        let object = "stale-internal.bin";
+        create_test_bucket(&ecstore, &bucket).await;
+
+        let mut metadata = HashMap::new();
+        rustfs_utils::http::insert_str(
+            &mut metadata,
+            rustfs_utils::http::SUFFIX_DATA_MOVEMENT_UPLOAD,
+            "cleanup-lock-test".to_string(),
+        );
+        let opts = ObjectOptions {
+            data_movement: true,
+            mod_time: Some(OffsetDateTime::now_utc() - time::Duration::hours(30)),
+            user_defined: metadata,
+            ..Default::default()
+        };
+        let upload = ecstore
+            .new_multipart_upload(&bucket, object, &opts)
+            .await
+            .expect("data movement multipart upload should be created");
+        let barrier = MultipartCommitBarrier::install(bucket.as_str(), object, MultipartCommitPause::PutPartAfterRename);
+        let put_store = ecstore.clone();
+        let put_bucket = bucket.clone();
+        let upload_id = upload.upload_id.clone();
+        let put_task = tokio::spawn(async move {
+            let mut data = PutObjReader::from_vec(vec![1, 2, 3, 4]);
+            put_store
+                .put_object_part(
+                    &put_bucket,
+                    object,
+                    &upload_id,
+                    1,
+                    &mut data,
+                    &ObjectOptions {
+                        data_movement: true,
+                        ..Default::default()
+                    },
+                )
+                .await
+        });
+        barrier.wait_until_paused().await;
+
+        let cleanup_store = ecstore.clone();
+        let mut cleanup_task = tokio::spawn(async move {
+            cleanup_stale_multipart_uploads_once_at(
+                cleanup_store,
+                OffsetDateTime::now_utc(),
+                StdDuration::from_secs(24 * 60 * 60),
+            )
+            .await
+        });
+        assert!(
+            tokio::time::timeout(StdDuration::from_millis(200), &mut cleanup_task)
+                .await
+                .is_err(),
+            "stale cleanup must wait for the in-flight part commit upload lock"
+        );
+
+        barrier.release();
+        put_task
+            .await
+            .expect("part upload task should join")
+            .expect("part upload should commit before stale cleanup");
+        let deleted = cleanup_task.await.expect("stale cleanup task should join");
+        assert!(deleted >= 1, "stale cleanup should proceed after the part commit releases its lock");
+    }
+
    #[tokio::test]
    #[serial]
    async fn stale_multipart_cleanup_applies_abort_incomplete_lifecycle_before_default_expiry() {
@@ -12000,6 +12275,58 @@ mod tests {
        assert!(is_err_invalid_upload_id(&err));
    }

+    #[tokio::test]
+    #[serial]
+    async fn stale_multipart_cleanup_excludes_data_movement_from_abort_lifecycle() {
+        let (_paths, ecstore) = setup_test_env().await;
+        let bucket = format!("stale-internal-lifecycle-{}", Uuid::new_v4().simple());
+        let object = "logs/internal/object.bin";
+        create_test_bucket(&ecstore, &bucket).await;
+        set_abort_incomplete_lifecycle(&bucket, "logs/", 0).await;
+
+        let initiated = OffsetDateTime::now_utc() - time::Duration::minutes(5);
+        let mut metadata = HashMap::new();
+        rustfs_utils::http::insert_str(
+            &mut metadata,
+            rustfs_utils::http::SUFFIX_DATA_MOVEMENT_UPLOAD,
+            "lifecycle-exclusion-test".to_string(),
+        );
+        let upload = ecstore
+            .new_multipart_upload(
+                &bucket,
+                object,
+                &ObjectOptions {
+                    data_movement: true,
+                    mod_time: Some(initiated),
+                    user_defined: metadata,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("data movement multipart upload should be created");
+
+        let deleted = cleanup_stale_multipart_uploads_once_at(
+            ecstore.clone(),
+            OffsetDateTime::now_utc(),
+            StdDuration::from_secs(7 * 24 * 60 * 60),
+        )
+        .await;
+        assert_eq!(deleted, 0, "bucket lifecycle must not remove active data movement uploads");
+
+        ecstore
+            .get_multipart_info(
+                &bucket,
+                object,
+                &upload.upload_id,
+                &ObjectOptions {
+                    data_movement: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("active data movement upload should remain available");
+    }
+
    #[tokio::test]
    #[serial]
    async fn stale_multipart_cleanup_applies_abort_lifecycle_with_size_filter() {
@@ -759,6 +759,10 @@ pub struct ManualTransitionWorkerResultRecord {
 }

 impl ManualTransitionWorkerResultRecord {
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
    pub fn new(job_id: Uuid, task_key: impl Into<String>, result: ManualTransitionWorkerResult) -> Self {
        Self::new_with_reason(job_id, task_key, result, None)
    }
@@ -1257,6 +1261,10 @@ pub(crate) async fn save_manual_transition_task_if_absent(
    }
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn load_manual_transition_task_record(
    api: Arc<ECStore>,
    job_id: Uuid,
@@ -1320,6 +1328,10 @@ async fn scan_manual_transition_task_journal(api: Arc<ECStore>, job_id: Uuid) ->
    }
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn load_manual_transition_worker_result_stats(
    api: Arc<ECStore>,
    job_id: Uuid,
@@ -1455,6 +1467,10 @@ async fn scan_manual_transition_worker_result_journal(
    }
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn reconcile_manual_transition_worker_results(
    api: Arc<ECStore>,
    job_id: Uuid,
@@ -19,7 +19,7 @@ pub mod core;
 pub mod evaluator;
 pub mod manual_transition_job;
 mod metadata_boundary;
-pub(crate) use metadata_boundary::get_expiry_configs;
+pub(crate) use metadata_boundary::{LifecycleExpiryConfigs, get_expiry_configs};
 mod object_lock_boundary;
 pub use self::core as lifecycle;
 mod replication_sink;
@@ -15,25 +15,35 @@
 use rustfs_common::metrics::IlmAction;

 use crate::bucket::lifecycle::lifecycle::ObjectOpts;
+use crate::bucket::replication::ReplicationLifecycleBridge;
 pub(crate) use crate::bucket::replication::ReplicationStatusType;
 #[cfg(test)]
 pub(crate) use crate::bucket::replication::VersionPurgeStatusType;
 pub(crate) use crate::bucket::replication::{
    DeleteReplicationConfigSnapshot, ReplicationObjectBridge, replication_state_to_filemeta,
 };
-use crate::bucket::replication::{ReplicationLifecycleBridge, ReplicationLifecycleConfig};
 use crate::storage_api_contracts::object::DeletedObject;

-pub(crate) type LifecycleReplicationConfig = ReplicationLifecycleConfig;
-
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_version_purge(obj: &ObjectOpts) -> bool {
    obj.version_purge_status.is_pending()
 }

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_object_replication(obj: &ObjectOpts) -> bool {
    replication_status_blocks_lifecycle(&obj.replication_status)
 }

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_lifecycle_replication(obj: &ObjectOpts) -> bool {
    has_pending_object_replication(obj) || has_pending_version_purge(obj)
 }
@@ -14,6 +14,10 @@

 use std::collections::HashMap;

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn decode_tags_to_map(tags: &str) -> HashMap<String, String> {
    crate::bucket::tagging::decode_tags_to_map(tags)
 }
@@ -331,6 +331,10 @@ where
    persist_tier_delete_journal_entry(api, &committed).await
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn abort_tier_delete_journal_entry<S>(api: Arc<S>, je: &Jentry) -> std::io::Result<()>
 where
    S: ObjectOperations<
@@ -148,6 +148,10 @@ struct RecoveryCursor {
    object: String,
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn recover_tier_free_versions(
    api: Arc<ECStore>,
    limit: usize,
@@ -80,7 +80,10 @@ impl LastDayTierStats {
        }
    }

-    #[allow(dead_code)]
+    #[allow(
+        dead_code,
+        reason = "asserted by this file's tests; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
    fn merge(&self, m: LastDayTierStats) -> LastDayTierStats {
        let mut cl = self.clone();
        let mut cm = m;
@@ -177,9 +177,10 @@ fn should_record_remote_delete_failure(err: &std::io::Error) -> bool {
 }

 #[derive(Default)]
-#[allow(dead_code)]
 struct ObjSweeper {
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    object: String,
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    bucket: String,
    version_id: Option<Uuid>,
    versioned: bool,
@@ -191,9 +192,9 @@ struct ObjSweeper {
    remote_object: String,
 }

-#[allow(dead_code)]
 impl ObjSweeper {
    #[allow(clippy::new_ret_no_self)]
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub async fn new(bucket: &str, object: &str) -> Result<Self, std::io::Error> {
        Ok(Self {
            object: object.into(),
@@ -202,17 +203,20 @@ impl ObjSweeper {
        })
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub fn with_version(&mut self, vid: Option<Uuid>) -> &Self {
        self.version_id = vid.clone();
        self
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub fn with_versioning(&mut self, versioned: bool, suspended: bool) -> &Self {
        self.versioned = versioned;
        self.suspended = suspended;
        self
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub fn get_opts(&self) -> lifecycle::ObjectOpts {
        let mut opts = ObjectOpts {
            version_id: self.version_id.clone(),
@@ -226,6 +230,7 @@ impl ObjSweeper {
        opts
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub fn set_transition_state(&mut self, info: TransitionedObject) {
        self.transition_tier = info.tier;
        self.transition_status = info.status;
@@ -266,6 +271,7 @@ impl ObjSweeper {
        None
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    pub async fn sweep(&self, api: Arc<ECStore>) {
        let Some(je) = self.should_remove_remote_object() else {
            return;
@@ -385,6 +391,10 @@ impl ExpiryOp for Jentry {
    }
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn delete_object_from_remote_tier(obj_name: &str, rv_id: &str, tier_name: &str) -> Result<(), std::io::Error> {
    let result = delete_object_from_remote_tier_raw(obj_name, rv_id, tier_name).await;
    if let Err(err) = &result
@@ -395,6 +405,10 @@ pub async fn delete_object_from_remote_tier(obj_name: &str, rv_id: &str, tier_na
    result
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_object_from_remote_tier_raw(obj_name: &str, rv_id: &str, tier_name: &str) -> Result<(), std::io::Error> {
    #[cfg(test)]
    if let Some(result) = run_remote_tier_delete_test_hook(obj_name, rv_id, tier_name) {
@@ -405,6 +419,10 @@ async fn delete_object_from_remote_tier_raw(obj_name: &str, rv_id: &str, tier_na
    delete_object_from_remote_tier_raw_with_manager(obj_name, rv_id, tier_name, &tier_config_mgr).await
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_object_from_remote_tier_raw_with_manager(
    obj_name: &str,
    rv_id: &str,
@@ -485,6 +503,10 @@ pub enum RemoteTierDeleteOutcome {
    AlreadyRemoved,
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn delete_object_from_remote_tier_idempotent(
    obj_name: &str,
    rv_id: &str,
@@ -50,8 +50,16 @@ pub type Result<T> = std::result::Result<T, TransitionTransactionError>;
 #[derive(Debug, thiserror::Error)]
 pub enum TransitionTransactionError {
    #[error("transition transaction already exists")]
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
    AlreadyExists,
    #[error("transition transaction is not found")]
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
    NotFound,
    #[error("transition transaction is corrupt: {0}")]
    Corrupt(&'static str),
@@ -50,6 +50,75 @@ use uuid::Uuid;

 const BUCKET_METADATA_REFRESH_INTERVAL: Duration = Duration::from_secs(15 * 60);

+#[cfg(any(test, feature = "test-util"))]
+struct ConfigWriteLockProbeState {
+    bucket: String,
+    arrived: tokio::sync::Notify,
+}
+
+#[cfg(any(test, feature = "test-util"))]
+static CONFIG_WRITE_LOCK_PROBES: std::sync::OnceLock<StdMutex<Vec<Arc<ConfigWriteLockProbeState>>>> = std::sync::OnceLock::new();
+
+#[cfg(any(test, feature = "test-util"))]
+#[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
+pub struct ConfigWriteLockProbe {
+    state: Arc<ConfigWriteLockProbeState>,
+}
+
+#[cfg(any(test, feature = "test-util"))]
+impl ConfigWriteLockProbe {
+    #[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
+    pub fn install(bucket: &str) -> Self {
+        let state = Arc::new(ConfigWriteLockProbeState {
+            bucket: bucket.to_string(),
+            arrived: tokio::sync::Notify::new(),
+        });
+        let mut probes = CONFIG_WRITE_LOCK_PROBES
+            .get_or_init(|| StdMutex::new(Vec::new()))
+            .lock()
+            .expect("config write lock probe mutex should not poison");
+        assert!(
+            !probes.iter().any(|current| current.bucket == state.bucket),
+            "config write lock probe must be unique for a bucket"
+        );
+        probes.push(Arc::clone(&state));
+        drop(probes);
+        Self { state }
+    }
+
+    #[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
+    pub async fn wait_until_attempted(&self) {
+        tokio::time::timeout(Duration::from_secs(30), self.state.arrived.notified())
+            .await
+            .expect("bucket config update should attempt the transaction lock");
+    }
+}
+
+#[cfg(any(test, feature = "test-util"))]
+impl Drop for ConfigWriteLockProbe {
+    fn drop(&mut self) {
+        let mut probes = CONFIG_WRITE_LOCK_PROBES
+            .get_or_init(|| StdMutex::new(Vec::new()))
+            .lock()
+            .expect("config write lock probe mutex should not poison");
+        probes.retain(|state| !Arc::ptr_eq(state, &self.state));
+    }
+}
+
+#[cfg(any(test, feature = "test-util"))]
+fn notify_config_write_lock_attempt(bucket: &str) {
+    let probe = CONFIG_WRITE_LOCK_PROBES
+        .get_or_init(|| StdMutex::new(Vec::new()))
+        .lock()
+        .expect("config write lock probe mutex should not poison")
+        .iter()
+        .find(|probe| probe.bucket == bucket)
+        .cloned();
+    if let Some(probe) = probe {
+        probe.arrived.notify_one();
+    }
+}
+
 #[derive(Clone, Copy)]
 enum MetadataLoadMode {
    Initial,
@@ -590,6 +659,41 @@ pub async fn update_under_transaction_lock(
    update_under_config_write_guard(get_bucket_metadata_sys()?, guard, config_file, data).await
 }

+/// Clear one config file while the caller holds this bucket's transaction lock.
+pub async fn delete_under_transaction_lock(
+    guard: &BucketMetadataMutationGuard,
+    bucket: &str,
+    config_file: &str,
+) -> Result<OffsetDateTime> {
+    guard.ensure_valid(bucket)?;
+    delete_under_config_write_guard(get_bucket_metadata_sys()?, guard, config_file).await
+}
+
+pub async fn update_quota_if_incarnation(
+    bucket: &str,
+    data: Vec<u8>,
+    expected_incarnation_id: Uuid,
+    proof: &crate::services::notification_sys::CrossPoolFenceFleetProofToken,
+) -> Result<OffsetDateTime> {
+    let sys = get_bucket_metadata_sys()?;
+    let guard = Box::pin(acquire_config_write_guard_for_incarnation(
+        sys.clone(),
+        bucket,
+        Some(expected_incarnation_id),
+    ))
+    .await?;
+    if !crate::services::notification_sys::cross_pool_fence_fleet_proof_matches(proof) {
+        return Err(Error::NamespaceLockQuorumUnavailable {
+            mode: "quota_capability",
+            bucket: bucket.to_string(),
+            object: rustfs_config::QUOTA_CONFIG_FILE.to_string(),
+            required: 1,
+            achieved: 0,
+        });
+    }
+    update_under_config_write_guard(sys, &guard, rustfs_config::QUOTA_CONFIG_FILE, data).await
+}
+
 pub async fn update_bucket_targets_under_transaction_lock(
    guard: &BucketMetadataMutationGuard,
    bucket: &str,
@@ -704,6 +808,14 @@ pub async fn acquire_bucket_metadata_transaction_lock(bucket: &str) -> Result<Bu
    acquire_config_write_guard(get_bucket_metadata_sys()?, bucket).await
 }

+/// Acquire the bucket transaction lock only if its incarnation still matches.
+pub async fn acquire_bucket_metadata_transaction_lock_for_incarnation(
+    bucket: &str,
+    expected_incarnation_id: Uuid,
+) -> Result<BucketMetadataMutationGuard> {
+    acquire_config_write_guard_for_incarnation(get_bucket_metadata_sys()?, bucket, Some(expected_incarnation_id)).await
+}
+
 pub(crate) async fn acquire_bucket_metadata_transaction_lock_in(
    ctx: &crate::runtime::instance::InstanceContext,
    bucket: &str,
@@ -734,7 +846,26 @@ async fn acquire_transaction_lock_with_sys(
    let lock = api
        .new_ns_lock(RUSTFS_META_BUCKET, &bucket_metadata_transaction_lock_key(bucket))
        .await?;
-    Ok(lock.get_write_lock(crate::set_disk::get_lock_acquire_timeout()).await?)
+    let acquire = lock.get_write_lock(crate::set_disk::get_lock_acquire_timeout());
+    #[cfg(any(test, feature = "test-util"))]
+    {
+        tokio::pin!(acquire);
+        let mut notified = false;
+        let guard = futures::future::poll_fn(|cx| match std::future::Future::poll(acquire.as_mut(), cx) {
+            std::task::Poll::Pending => {
+                if !notified {
+                    notify_config_write_lock_attempt(bucket);
+                    notified = true;
+                }
+                std::task::Poll::Pending
+            }
+            std::task::Poll::Ready(result) => std::task::Poll::Ready(result),
+        })
+        .await?;
+        Ok(guard)
+    }
+    #[cfg(not(any(test, feature = "test-util")))]
+    Ok(acquire.await?)
 }

 /// The lock resource name is deliberately still the `bucket-targets` one it
@@ -762,6 +893,10 @@ pub async fn get_bucket_policy_raw(bucket: &str) -> Result<(String, OffsetDateTi
    bucket_meta_sys.get_bucket_policy_raw(bucket).await
 }

+#[allow(
+    dead_code,
+    reason = "free-function facade over the live BucketMetadataSys::get_bucket_acl_config; no caller in this port (backlog#1823)"
+)]
 pub async fn get_bucket_acl_config(bucket: &str) -> Result<(String, OffsetDateTime)> {
    let bucket_meta_sys_lock = get_bucket_metadata_sys()?;
    let bucket_meta_sys = bucket_meta_sys_lock.read().await;
@@ -889,6 +1024,37 @@ pub(crate) async fn get_object_lock_config_and_incarnation_from_disk_in(
    }
 }

+/// Re-read the quota configuration and bucket incarnation from the same
+/// authoritative metadata blob while the caller holds the bucket metadata
+/// transaction read lock.
+pub(crate) async fn get_quota_config_and_incarnation_from_disk_in(
+    ctx: &crate::runtime::instance::InstanceContext,
+    bucket: &str,
+) -> Result<(Option<BucketQuota>, Uuid, OffsetDateTime)> {
+    let bucket_meta_sys_lock = bucket_metadata_sys_of(ctx)?;
+    let bucket_meta_sys = bucket_meta_sys_lock.read().await.clone();
+
+    match bucket_meta_sys
+        .read_authoritative_metadata_from_disk_under_transaction_lock(bucket)
+        .await?
+    {
+        BucketMetadataAuthority::Authoritative(metadata)
+            if metadata.bucket_incarnation_sidecar && !metadata.bucket_incarnation_id.is_nil() =>
+        {
+            Ok((
+                metadata.quota_config.clone(),
+                metadata.bucket_incarnation_id,
+                metadata.quota_config_updated_at,
+            ))
+        }
+        BucketMetadataAuthority::Authoritative(_) => {
+            Err(Error::other(format!("bucket incarnation metadata is not authoritative: {bucket}")))
+        }
+        BucketMetadataAuthority::MissingBucket => Err(Error::BucketNotFound(bucket.to_string())),
+        BucketMetadataAuthority::Fabricated => Err(Error::other(format!("bucket quota metadata is not authoritative: {bucket}"))),
+    }
+}
+
 pub async fn get_replication_config(bucket: &str) -> Result<(ReplicationConfiguration, OffsetDateTime)> {
    let bucket_meta_sys_lock = get_bucket_metadata_sys()?;
    let bucket_meta_sys = bucket_meta_sys_lock.read().await;
@@ -945,6 +1111,10 @@ pub async fn get_config_from_disk(bucket: &str) -> Result<BucketMetadata> {
    bucket_meta_sys.get_config_from_disk(bucket).await
 }

+#[allow(
+    dead_code,
+    reason = "ambient-facade variant of the live created_at_in; no caller in this port (backlog#1823)"
+)]
 pub async fn created_at(bucket: &str) -> Result<OffsetDateTime> {
    let bucket_meta_sys_lock = get_bucket_metadata_sys()?;
    let bucket_meta_sys = bucket_meta_sys_lock.read().await;
@@ -1458,6 +1628,7 @@ impl BucketMetadataSys {
    /// [`Self::update`], with the payload computed from the loaded metadata
    /// instead of supplied up front. Loads through this system's own store so
    /// the read and the persisted write target the same instance.
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
    async fn update_config_with<F>(&self, bucket: &str, config_file: &str, mutate: F) -> Result<OffsetDateTime>
    where
        F: FnOnce(&BucketMetadata) -> Result<Vec<u8>> + Send,
@@ -1562,6 +1733,7 @@ impl BucketMetadataSys {
    /// A miss is never published as an authoritative default, and a snapshot
    /// read before delete plus same-name recreation cannot replace the new
    /// generation.
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
    pub(crate) async fn reload_from_store(&self, bucket: &str) -> Result<()> {
        if is_meta_bucketname(bucket) {
            return Err(Error::other("errInvalidArgument"));
@@ -13,7 +13,6 @@
 // limitations under the License.

 // #730: bucket subsystems still contain staged ECStore migration code.
-#![allow(dead_code)]

 pub mod bandwidth;
 pub mod bucket_target_sys;
@@ -136,6 +136,7 @@ pub fn add_years(dt: OffsetDateTime, years: i32) -> OffsetDateTime {

 /// Check if an object has legal hold enabled.
 /// Returns true if legal hold is ON.
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn has_legal_hold(user_defined: &std::collections::HashMap<String, String>) -> bool {
    let lhold = objectlock::get_object_legalhold_meta(user_defined);
    matches!(lhold.status, Some(ref st) if st.as_str() == ObjectLockLegalHoldStatus::ON)
@@ -151,6 +152,7 @@ fn has_legal_hold(user_defined: &std::collections::HashMap<String, String>) -> b
 /// # Returns
 /// * `true` if the object is locked (cannot be deleted/modified)
 /// * `false` if the object is not locked
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn is_object_locked_by_metadata(user_defined: &std::collections::HashMap<String, String>, is_delete_marker: bool) -> bool {
    // Delete markers are never locked
    if is_delete_marker {
@@ -52,6 +52,7 @@ impl QuotaChecker {
    ) -> Result<QuotaCheckResult, QuotaError> {
        let start_time = Instant::now();
        let quota_config = self.get_quota_config(bucket).await?;
+        let uses_durable_reservations = quota_config.uses_durable_reservations();

        // If no quota limit is set, allow operation
        let quota_limit = match quota_config.quota {
@@ -67,6 +68,7 @@ impl QuotaChecker {
                    quota_limit: None,
                    operation_size,
                    remaining: None,
+                    uses_durable_reservations,
                });
            }
            Some(q) => q,
@@ -74,14 +76,17 @@ impl QuotaChecker {

        let current_usage = self.get_real_time_usage(bucket).await?;

+        let admission_size = if uses_durable_reservations { 0 } else { operation_size };
        let expected_usage = match operation {
-            QuotaOperation::PutObject | QuotaOperation::PostObject | QuotaOperation::CopyObject => current_usage + operation_size,
+            QuotaOperation::PutObject | QuotaOperation::PostObject | QuotaOperation::CopyObject => {
+                current_usage.saturating_add(admission_size)
+            }
            QuotaOperation::DeleteObject => current_usage.saturating_sub(operation_size),
        };

        let allowed = match operation {
            QuotaOperation::PutObject | QuotaOperation::PostObject | QuotaOperation::CopyObject => {
-                quota_config.check_operation_allowed(current_usage, operation_size)
+                quota_config.check_operation_allowed(current_usage, admission_size)
            }
            QuotaOperation::DeleteObject => true,
        };
@@ -105,6 +110,7 @@ impl QuotaChecker {
            quota_limit: Some(quota_limit),
            operation_size,
            remaining,
+            uses_durable_reservations,
        };

        let duration = start_time.elapsed();
@@ -158,6 +164,26 @@ impl QuotaChecker {
            .await
    }

+    pub async fn set_durable_quota_config_if_incarnation(
+        &mut self,
+        bucket: &str,
+        quota: BucketQuota,
+        expected_incarnation_id: uuid::Uuid,
+        proof: &crate::services::notification_sys::CrossPoolFenceFleetProofToken,
+    ) -> Result<OffsetDateTime, QuotaError> {
+        let json_data = serde_json::to_vec(&quota).map_err(|e| QuotaError::InvalidConfig {
+            reason: format!("Failed to serialize quota config: {}", e),
+        })?;
+        let start_time = Instant::now();
+        let updated_at =
+            crate::bucket::metadata_sys::update_quota_if_incarnation(bucket, json_data, expected_incarnation_id, proof)
+                .await
+                .map_err(QuotaError::StorageError)?;
+
+        rustfs_common::metrics::Metrics::inc_time(Metric::QuotaSync, start_time.elapsed());
+        Ok(updated_at)
+    }
+
    async fn set_quota_config_for_incarnation(
        &mut self,
        bucket: &str,
@@ -355,6 +381,7 @@ mod tests {
            quota_limit: None,
            operation_size: 1024,
            remaining: None,
+            uses_durable_reservations: false,
        };

        assert!(result.allowed);
@@ -378,4 +405,13 @@ mod tests {
        let allowed = quota.check_operation_allowed(512, 1024);
        assert!(!allowed);
    }
+
+    #[test]
+    fn legacy_quota_rejects_full_operation_while_v1_defers_net_growth() {
+        let legacy: BucketQuota = serde_json::from_str(r#"{"quota":5}"#).expect("legacy quota should parse");
+        let durable = BucketQuota::new(Some(5));
+
+        assert!(!legacy.check_operation_allowed(4, 2));
+        assert!(durable.uses_durable_reservations());
+    }
 }
@@ -13,40 +13,100 @@
 // limitations under the License.

 pub mod checker;
+pub(crate) mod reservation;

 use crate::error::Result;
 use rustfs_config::{
    QUOTA_API_PATH, QUOTA_EXCEEDED_ERROR_CODE, QUOTA_INTERNAL_ERROR_CODE, QUOTA_INVALID_CONFIG_ERROR_CODE,
    QUOTA_NOT_FOUND_ERROR_CODE,
 };
-use serde::{Deserialize, Serialize};
+use serde::{Deserialize, Deserializer, Serialize, Serializer, de::Error as _};
 use thiserror::Error;
 use time::OffsetDateTime;

 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub enum QuotaType {
-    /// Hard quota: reject immediately when exceeded
+    /// Hard quota accounting.
    #[default]
    #[serde(alias = "HARD", alias = "hard")]
    Hard,
 }

+pub(crate) const QUOTA_RESERVATION_PROTOCOL_V1: u32 = 1;
+
 /// Bucket quota configuration. quota_type defaults to Hard when omitted.
-#[derive(Debug, Deserialize, Serialize, Default, Clone, PartialEq)]
+#[derive(Debug, Default, Clone, PartialEq)]
 pub struct BucketQuota {
-    #[serde(default)]
    pub quota: Option<u64>,
    /// Defaults to Hard when missing.
-    #[serde(default)]
    pub quota_type: QuotaType,
+    /// Optional durable reservation protocol. The wire format gives older
+    /// nodes a zero hard quota so a mixed-version fleet fails closed.
+    pub reservation_protocol: Option<u32>,
    /// Timestamp when this quota configuration was set (for audit purposes)
-    #[serde(default, with = "time::serde::rfc3339::option")]
    pub created_at: Option<OffsetDateTime>,
    /// Accept updated_at for compatibility; not used.
-    #[serde(default, with = "time::serde::rfc3339::option", skip_serializing_if = "Option::is_none")]
    pub updated_at: Option<OffsetDateTime>,
 }

+#[derive(Deserialize, Serialize)]
+struct BucketQuotaWire {
+    #[serde(default)]
+    quota: Option<u64>,
+    #[serde(default)]
+    quota_type: QuotaType,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    reservation_protocol: Option<u32>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    reservation_quota: Option<u64>,
+    #[serde(default, with = "time::serde::rfc3339::option")]
+    created_at: Option<OffsetDateTime>,
+    #[serde(default, with = "time::serde::rfc3339::option", skip_serializing_if = "Option::is_none")]
+    updated_at: Option<OffsetDateTime>,
+}
+
+impl Serialize for BucketQuota {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let durable = self.uses_durable_reservations();
+        BucketQuotaWire {
+            quota: if durable { Some(0) } else { self.quota },
+            quota_type: self.quota_type.clone(),
+            reservation_protocol: self.reservation_protocol,
+            reservation_quota: if durable { self.quota } else { None },
+            created_at: self.created_at,
+            updated_at: self.updated_at,
+        }
+        .serialize(serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for BucketQuota {
+    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let wire = BucketQuotaWire::deserialize(deserializer)?;
+        let quota = if wire.reservation_protocol == Some(QUOTA_RESERVATION_PROTOCOL_V1) {
+            Some(
+                wire.reservation_quota
+                    .ok_or_else(|| D::Error::custom("reservation_quota is required for reservation protocol v1"))?,
+            )
+        } else {
+            wire.quota
+        };
+        Ok(Self {
+            quota,
+            quota_type: wire.quota_type,
+            reservation_protocol: wire.reservation_protocol,
+            created_at: wire.created_at,
+            updated_at: wire.updated_at,
+        })
+    }
+}
+
 impl BucketQuota {
    /// Serialize to JSON bytes. Same format as parse_all_configs.
    pub fn marshal_msg(&self) -> Result<Vec<u8>> {
@@ -63,6 +123,7 @@ impl BucketQuota {
        Self {
            quota,
            quota_type: QuotaType::Hard,
+            reservation_protocol: quota.map(|_| QUOTA_RESERVATION_PROTOCOL_V1),
            created_at: Some(now),
            updated_at: None,
        }
@@ -72,7 +133,19 @@ impl BucketQuota {
        self.quota
    }

+    pub fn uses_durable_reservations(&self) -> bool {
+        self.reservation_protocol == Some(QUOTA_RESERVATION_PROTOCOL_V1)
+    }
+
+    pub fn has_unsupported_reservation_protocol(&self) -> bool {
+        self.reservation_protocol
+            .is_some_and(|version| version != QUOTA_RESERVATION_PROTOCOL_V1)
+    }
+
    pub fn check_operation_allowed(&self, current_usage: u64, operation_size: u64) -> bool {
+        if operation_size == 0 {
+            return true;
+        }
        if let Some(quota_limit) = self.quota {
            current_usage.saturating_add(operation_size) <= quota_limit
        } else {
@@ -94,6 +167,7 @@ pub struct QuotaCheckResult {
    pub quota_limit: Option<u64>,
    pub operation_size: u64,
    pub remaining: Option<u64>,
+    pub uses_durable_reservations: bool,
 }

 #[derive(Debug)]
@@ -119,6 +193,7 @@ pub enum QuotaError {
 }

 #[derive(Debug, Serialize)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub struct QuotaErrorResponse {
    #[serde(rename = "Code")]
    pub code: String,
@@ -134,6 +209,7 @@ pub struct QuotaErrorResponse {
 }

 impl QuotaErrorResponse {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
    pub fn new(quota_error: &QuotaError, request_id: &str, host_id: &str) -> Self {
        match quota_error {
            QuotaError::QuotaExceeded { .. } => Self {
@@ -210,7 +286,57 @@ mod tests {
        let buf = q.marshal_msg().expect("marshal");
        let restored = BucketQuota::unmarshal(&buf).expect("unmarshal");
        assert_eq!(q.quota, restored.quota);
-        assert_eq!(q.quota_type, restored.quota_type);
+        assert_eq!(restored.quota_type, QuotaType::Hard);
+        assert_eq!(restored.reservation_protocol, Some(QUOTA_RESERVATION_PROTOCOL_V1));
+    }
+
+    #[test]
+    fn clearing_quota_keeps_the_legacy_compatible_type() {
+        let quota = BucketQuota::new(None);
+
+        assert_eq!(quota.quota_type, QuotaType::Hard);
+        assert_eq!(quota.reservation_protocol, None);
+        assert!(!quota.uses_durable_reservations());
+    }
+
+    #[test]
+    fn durable_quota_makes_legacy_nodes_fail_closed() {
+        let json = serde_json::to_vec(&BucketQuota::new(Some(2048))).expect("durable quota should serialize");
+        let quota: BucketQuota = serde_json::from_slice(&json).expect("current quota version should parse");
+        assert!(quota.uses_durable_reservations());
+        assert_eq!(quota.quota, Some(2048));
+
+        #[derive(Deserialize)]
+        enum LegacyQuotaType {
+            Hard,
+        }
+        #[derive(Deserialize)]
+        struct LegacyBucketQuota {
+            quota: Option<u64>,
+            quota_type: LegacyQuotaType,
+        }
+        let legacy = serde_json::from_slice::<LegacyBucketQuota>(&json)
+            .expect("legacy readers should ignore the reservation protocol field");
+        assert_eq!(legacy.quota, Some(0));
+        assert!(matches!(legacy.quota_type, LegacyQuotaType::Hard));
+    }
+
+    #[test]
+    fn unknown_reservation_protocol_does_not_activate_v1() {
+        let quota: BucketQuota =
+            serde_json::from_str(r#"{"quota":0,"quota_type":"Hard","reservation_protocol":2,"reservation_quota":2048}"#)
+                .expect("future protocol should remain parseable");
+
+        assert!(!quota.uses_durable_reservations());
+        assert!(quota.has_unsupported_reservation_protocol());
+    }
+
+    #[test]
+    fn reservation_protocol_v1_requires_reservation_quota() {
+        let err = serde_json::from_str::<BucketQuota>(r#"{"quota":0,"quota_type":"Hard","reservation_protocol":1}"#)
+            .expect_err("v1 without its authoritative quota must fail closed");
+
+        assert!(err.to_string().contains("reservation_quota is required"));
    }

    /// unmarshal accepts format without quota_type
@@ -60,7 +60,7 @@ pub use replication_filemeta_boundary::{
 pub(crate) use replication_filemeta_boundary::{
    replication_state_from_filemeta, replication_status_from_filemeta, version_purge_status_from_filemeta,
 };
-pub(crate) use replication_lifecycle_bridge::{ReplicationLifecycleBridge, ReplicationLifecycleConfig};
+pub(crate) use replication_lifecycle_bridge::ReplicationLifecycleBridge;
 pub(crate) use replication_migration_bridge::ReplicationMigrationBridge;
 pub use replication_object_bridge::ReplicationObjectBridge;
 pub use replication_object_config::{DeleteReplicationConfigSnapshot, ReplicationConfig};
@@ -81,6 +81,6 @@ pub use replication_queue_boundary::{
 pub use replication_resync_boundary::{BucketReplicationResyncStatus, ResyncOpts, TargetReplicationResyncStatus};
 pub use replication_scanner_bridge::ReplicationScannerBridge;
 pub use replication_state::{ReplicationStats, RuntimeReplicationTargetBacklog};
-pub use replication_stats_boundary::{BucketReplicationStats, BucketStats};
+pub use replication_stats_boundary::{BucketReplicationStat, BucketReplicationStats, BucketStats, InQueueMetric, XferStats};
 pub use replication_storage_boundary::{ReplicationObjectIO, ReplicationStorage};
 pub(crate) use replication_target_config_bridge::ReplicationTargetConfigBridge;
@@ -37,6 +37,10 @@ impl ReplicationConfigStore {
        com::read_config_limited(api, file, max_bytes).await
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    pub(crate) async fn read_no_lock<S>(api: Arc<S>, file: &str) -> Result<Vec<u8>>
    where
        S: ReplicationObjectIO,
@@ -24,15 +24,27 @@ use super::replication_storage_boundary::{
    DeletedObject, ObjectInfo, ObjectOptions, ObjectToDelete, deleted_object_for_replication,
 };

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) type ReplicationLifecycleConfig = ReplicationConfig;

 pub(crate) struct ReplicationLifecycleBridge;

 impl ReplicationLifecycleBridge {
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn new_config(config: ReplicationConfiguration) -> ReplicationLifecycleConfig {
        ReplicationConfig::new(Some(config), None)
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn has_pending_version_purge(
        config: &ReplicationLifecycleConfig,
        object_name: &str,
@@ -45,6 +57,10 @@ impl ReplicationLifecycleBridge {
                .is_some_and(|config| config.has_active_rules(object_name, true))
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) async fn check_delete_replication(
        bucket: &str,
        object: &ObjectToDelete,
@@ -54,6 +70,10 @@ impl ReplicationLifecycleBridge {
        check_replicate_delete(bucket, object, source, opts, None).await
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn version_delete_replication_state(decision: &ReplicateDecision) -> ReplicationState {
        let pending_status = decision.pending_status();
        ReplicationState {
@@ -19,17 +19,33 @@ use time::OffsetDateTime;
 use super::replication_error_boundary::Result;
 use crate::bucket::msgp_decode;

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) struct ReplicationMsgpCodec;

 impl ReplicationMsgpCodec {
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn read_ext8_time<R: Read>(rd: &mut R) -> Result<OffsetDateTime> {
        msgp_decode::read_msgp_ext8_time(rd)
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn skip_value<R: Read>(rd: &mut R) -> Result<()> {
        msgp_decode::skip_msgp_value(rd)
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) fn write_time<W: Write>(wr: &mut W, time: OffsetDateTime) -> Result<()> {
        msgp_decode::write_msgp_time(wr, time)
    }
@@ -77,6 +77,10 @@ impl ReplicationObjectBridge {
        load_delete_request_config_in(ctx, bucket).await
    }

+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
    pub(crate) async fn delete_config_snapshot_in(
        ctx: &ReplicationInstanceContext,
        bucket: &str,
@@ -231,6 +231,10 @@ pub(crate) async fn load_delete_replication_config(
    delete_snapshot_from_metadata(ReplicationMetadataStore::delete_metadata(bucket).await?)
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 pub(crate) async fn load_delete_replication_config_in(
    ctx: &ReplicationInstanceContext,
    bucket: &str,
@@ -217,6 +217,10 @@ impl DurableMrfBacklogTracker {
    }
 }

+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 fn durable_mrf_backlog_tracker_from_entries(entries: &[MrfReplicateEntry]) -> DurableMrfBacklogTracker {
    let mut tracker = DurableMrfBacklogTracker {
        available: true,
@@ -712,6 +716,10 @@ pub struct ReplicationPool<S: ReplicationStorage> {

    // MRF worker lifecycle
    mrf_worker_cancellations: Mutex<Vec<CancellationToken>>,
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    mrf_stop_tx: Sender<()>,

    // Worker size tracking
@@ -940,6 +948,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Resizes worker priority and counts
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    pub async fn resize_worker_priority(
        &self,
        pri: ReplicationPriority,
@@ -1180,6 +1192,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Queues an MRF save operation
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    async fn queue_mrf_save(&self, entry: MrfReplicateEntry) {
        let _ = self.queue_mrf_save_admission(entry, "mrf_worker").await;
    }
@@ -1651,6 +1667,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Worker function for handling regular replication operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    async fn add_worker(
        &self,
        mut rx: Receiver<ReplicationOperation>,
@@ -1664,6 +1684,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Worker function for handling large object replication operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    async fn add_large_worker(
        &self,
        mut rx: Receiver<ReplicationOperation>,
@@ -1678,6 +1702,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Worker function for handling MRF (Most Recent Failures) operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    async fn add_mrf_worker(
        &self,
        mut rx: Receiver<ReplicationOperation>,
@@ -1691,6 +1719,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
    }

    /// Delete resync metadata from replication resync state in memory
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    pub async fn delete_resync_metadata(&self, bucket: &str) {
        let mut status_map = self.resyncer.status_map.write().await;
        status_map.remove(bucket);
@@ -21,11 +21,31 @@ pub(crate) use rustfs_replication::{
    should_count_head_proxy_failure,
 };

+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const RESYNC_META_FORMAT: u16 = rustfs_replication::resync::RESYNC_META_FORMAT;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const RESYNC_META_VERSION: u16 = rustfs_replication::resync::RESYNC_META_VERSION;
 pub(crate) const RESYNC_FILE_MAX_BYTES: usize = rustfs_replication::RESYNC_FILE_MAX_BYTES;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const WIRE_ZERO_TIME_UNIX: i64 = rustfs_replication::resync::WIRE_ZERO_TIME_UNIX;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const MRF_META_FORMAT: u16 = rustfs_replication::mrf::MRF_META_FORMAT;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const MRF_META_VERSION: u16 = rustfs_replication::mrf::MRF_META_VERSION;

 fn map_replication_error(err: rustfs_replication::Error) -> Error {
@@ -122,6 +122,10 @@ const REPLICATION_TARGET_OFFLINE_ERROR_MARKERS: &[&str] = &[
    "tcp connect error",
 ];

+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 const RESYNC_TIME_INTERVAL: TokioDuration = TokioDuration::from_secs(60);

 static WARNED_MONITOR_UNINIT: std::sync::Once = std::sync::Once::new();
@@ -328,6 +332,10 @@ fn bounded_resync_max_jobs(value: usize) -> usize {
 #[derive(Debug)]
 pub struct ReplicationResyncer {
    pub status_map: Arc<RwLock<HashMap<String, BucketReplicationResyncStatus>>>,
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    pub worker_size: usize,
    pub(crate) cancel_tokens: Arc<RwLock<HashMap<ResyncCancelKey, CancellationToken>>>,
    resync_admission: Arc<Semaphore>,
@@ -544,6 +552,10 @@ impl ReplicationResyncer {
            .is_some_and(|status| status.failed_count > 0)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    pub async fn persist_to_disk<S>(&self, cancel_token: CancellationToken, api: Arc<S>)
    where
        S: ReplicationObjectIO,
@@ -340,6 +340,10 @@ impl ReplicationStats {
    }

    /// Site replication update replica statistics
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
    fn sr_update_replica_stat(&self, size: i64) {
        self.sr_stats.replica_size.fetch_add(size, Ordering::Relaxed);
        self.sr_stats.replica_count.fetch_add(1, Ordering::Relaxed);
@@ -704,6 +708,12 @@ impl ReplicationStats {
        } else {
            BucketReplicationStats::new()
        };
+        // Stamp the serializable failure windows from the live samples: the
+        // samples themselves do not cross the peer-RPC wire, so this snapshot
+        // is what cluster aggregation and the metrics endpoints see.
+        for stat in replication_stats.stats.values_mut() {
+            stat.fail_stats.refresh_windows();
+        }
        let uptime = if cache.contains_key(bucket) {
            SystemTime::now()
                .duration_since(SystemTime::UNIX_EPOCH)
@@ -15,7 +15,9 @@
 #[cfg(test)]
 pub(crate) use rustfs_replication::FailStats;
 pub(crate) use rustfs_replication::{
-    ActiveWorkerStat, BucketReplicationStat, InQueueMetric, ProxyMetric, ProxyStatsCache, QueueCache, ReplicationMetricScope,
-    SRMetricsSummary, XferStats,
+    ActiveWorkerStat, ProxyMetric, ProxyStatsCache, QueueCache, ReplicationMetricScope, SRMetricsSummary,
 };
-pub use rustfs_replication::{BucketReplicationStats, BucketStats};
+// Public so the admin wire DTOs (rustfs/src/admin/replication_metrics_wire.rs)
+// can project the internal stats onto the minio-go response shapes through
+// the storage_api facade chain.
+pub use rustfs_replication::{BucketReplicationStat, BucketReplicationStats, BucketStats, InQueueMetric, XferStats};
@@ -27,8 +27,10 @@ use rustfs_utils::http::{
    AMZ_OBJECT_TAGGING, AMZ_SERVER_SIDE_ENCRYPTION, AMZ_SERVER_SIDE_ENCRYPTION_KMS_CONTEXT, AMZ_SERVER_SIDE_ENCRYPTION_KMS_ID,
    AMZ_STORAGE_CLASS, AMZ_TAG_COUNT, CACHE_CONTROL, CONTENT_DISPOSITION, CONTENT_ENCODING, CONTENT_LANGUAGE, CONTENT_TYPE,
    HeaderExt as _, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP,
-    SUFFIX_REPLICATION_ACTUAL_OBJECT_SIZE, SUFFIX_REPLICATION_SSEC_CRC, SUFFIX_TAGGING_TIMESTAMP, get_str, insert_header_map,
-    is_internal_key, is_object_encryption_marker, is_replication_stripped_encryption_key, ssec_replication_transport_header,
+    SUFFIX_REPLICATION_ACTUAL_OBJECT_SIZE, SUFFIX_REPLICATION_SSEC_CRC, SUFFIX_SOURCE_REPLICATION_LEGALHOLD_TIMESTAMP,
+    SUFFIX_SOURCE_REPLICATION_RETENTION_TIMESTAMP, SUFFIX_SOURCE_REPLICATION_TAGGING_TIMESTAMP, SUFFIX_TAGGING_TIMESTAMP,
+    get_str, insert_header_map, is_internal_key, is_object_encryption_marker, is_replication_stripped_encryption_key,
+    ssec_replication_transport_header,
 };
 use time::OffsetDateTime;
 use time::format_description::well_known::Rfc3339;
@@ -119,6 +121,27 @@ fn classify_replication_source_encryption(metadata: &HashMap<String, String>) ->
    }
 }

+fn is_legacy_source_replication_timestamp_key(key: &str) -> bool {
+    fn has_prefix_and_suffix(key: &str, prefix: &str, suffix: &str) -> bool {
+        let key = key.as_bytes();
+        key.len() == prefix.len() + suffix.len()
+            && key[..prefix.len()].eq_ignore_ascii_case(prefix.as_bytes())
+            && key[prefix.len()..].eq_ignore_ascii_case(suffix.as_bytes())
+    }
+
+    [
+        SUFFIX_SOURCE_REPLICATION_TAGGING_TIMESTAMP,
+        SUFFIX_SOURCE_REPLICATION_RETENTION_TIMESTAMP,
+        SUFFIX_SOURCE_REPLICATION_LEGALHOLD_TIMESTAMP,
+    ]
+    .iter()
+    .any(|suffix| {
+        ["x-rustfs-", "x-minio-"]
+            .iter()
+            .any(|prefix| has_prefix_and_suffix(key, prefix, suffix))
+    })
+}
+
 pub(crate) fn replication_object_is_ssec_encrypted(user_defined: &HashMap<String, String>) -> bool {
    rustfs_replication::is_ssec_encrypted(user_defined)
 }
@@ -176,6 +199,11 @@ pub(crate) fn replication_put_object_options(sc: &str, object_info: &ObjectInfo)
            continue;
        }

+        if is_legacy_source_replication_timestamp_key(key) {
+            meta.insert(format!("x-amz-meta-{key}"), value.to_string());
+            continue;
+        }
+
        if is_internal_key(key) || is_standard_header(key) {
            continue;
        }
@@ -259,15 +287,23 @@ pub(crate) fn replication_put_object_options(sc: &str, object_info: &ObjectInfo)

        if !tags.is_empty() {
            put_options.user_tags = tags;
-            put_options.internal.tagging_timestamp =
-                if let Some(timestamp) = get_str(&object_info.user_defined, SUFFIX_TAGGING_TIMESTAMP) {
-                    OffsetDateTime::parse(&timestamp, &Rfc3339)
-                        .map_err(|err| Error::other(format!("Failed to parse tagging timestamp: {err}")))?
-                } else {
-                    object_info.mod_time.unwrap_or(OffsetDateTime::UNIX_EPOCH)
-                };
        }
    }
+    // Load the stored tagging timestamp independently of whether any tags
+    // remain: DeleteObjectTagging leaves the object tagless but stamps this
+    // key, and the deletion's LWW timestamp must still reach the replica.
+    // With no stored key, fall back to mod_time only while tags exist
+    // (MinIO parity); a tagless object without the key was never tagged and
+    // keeps the epoch default (no header).
+    put_options.internal.tagging_timestamp = if let Some(timestamp) = get_str(&object_info.user_defined, SUFFIX_TAGGING_TIMESTAMP)
+    {
+        OffsetDateTime::parse(&timestamp, &Rfc3339)
+            .map_err(|err| Error::other(format!("Failed to parse tagging timestamp: {err}")))?
+    } else if !put_options.user_tags.is_empty() {
+        object_info.mod_time.unwrap_or(OffsetDateTime::UNIX_EPOCH)
+    } else {
+        OffsetDateTime::UNIX_EPOCH
+    };

    let metadata = &*object_info.user_defined;

@@ -283,13 +319,15 @@ pub(crate) fn replication_put_object_options(sc: &str, object_info: &ObjectInfo)
        put_options.cache_control = cache_control.to_string();
    }

-    if let Some(mode) = metadata.lookup(AMZ_OBJECT_LOCK_MODE) {
+    if let Some(mode) = metadata.lookup(AMZ_OBJECT_LOCK_MODE).filter(|mode| !mode.is_empty()) {
        put_options.mode = Some(ObjectLockRetentionMode::from(mode.to_uppercase().as_str()));
    }

    if let Some(retain_until_date) = metadata.lookup(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE) {
-        put_options.retain_until_date = OffsetDateTime::parse(retain_until_date, &Rfc3339)
-            .map_err(|err| Error::other(format!("Failed to parse retain until date: {err}")))?;
+        if !retain_until_date.is_empty() {
+            put_options.retain_until_date = OffsetDateTime::parse(retain_until_date, &Rfc3339)
+                .map_err(|err| Error::other(format!("Failed to parse retain until date: {err}")))?;
+        }
        put_options.internal.retention_timestamp =
            if let Some(timestamp) = get_str(&object_info.user_defined, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP) {
                OffsetDateTime::parse(&timestamp, &Rfc3339).unwrap_or(OffsetDateTime::UNIX_EPOCH)
@@ -694,6 +732,110 @@ mod tests {
        assert!(options.internal.replication_request);
    }

+    /// DeleteObjectTagging leaves the object tagless but stamps the
+    /// tagging-timestamp internal key; the deletion's LWW timestamp must
+    /// still be loaded (and therefore sent) so the replica can order the
+    /// deletion against concurrent tag edits.
+    #[test]
+    fn replication_put_options_carry_tagging_timestamp_after_tag_deletion() {
+        let mut metadata = std::collections::HashMap::new();
+        rustfs_utils::http::insert_str(&mut metadata, SUFFIX_TAGGING_TIMESTAMP, "2026-01-02T03:04:05Z".to_string());
+
+        let object_info = ObjectInfo {
+            user_defined: Arc::new(metadata),
+            user_tags: Arc::new(String::new()),
+            mod_time: Some(OffsetDateTime::UNIX_EPOCH),
+            version_id: Some(Uuid::nil()),
+            ..Default::default()
+        };
+
+        let (options, _) = replication_put_object_options("", &object_info).expect("build put options");
+
+        assert!(options.user_tags.is_empty());
+        assert_eq!(
+            options.internal.tagging_timestamp,
+            OffsetDateTime::parse("2026-01-02T03:04:05Z", &Rfc3339).expect("valid timestamp"),
+            "the stored tagging timestamp must load independently of remaining tags"
+        );
+
+        // A tagless object without the stored key was never tagged: the epoch
+        // default keeps the header unsent.
+        let untagged = ObjectInfo {
+            user_tags: Arc::new(String::new()),
+            mod_time: Some(OffsetDateTime::from_unix_timestamp(1_700_000_000).expect("timestamp")),
+            version_id: Some(Uuid::nil()),
+            ..Default::default()
+        };
+        let (options, _) = replication_put_object_options("", &untagged).expect("build put options");
+        assert_eq!(options.internal.tagging_timestamp, OffsetDateTime::UNIX_EPOCH);
+    }
+
+    #[test]
+    fn replication_put_options_do_not_promote_legacy_user_timestamp_metadata() {
+        let legacy_keys = [
+            "x-rustfs-source-replication-tagging-timestamp",
+            "x-rustfs-source-replication-retention-timestamp",
+            "x-rustfs-source-replication-legalhold-timestamp",
+            "x-minio-source-replication-tagging-timestamp",
+            "x-minio-source-replication-retention-timestamp",
+            "x-minio-source-replication-legalhold-timestamp",
+        ];
+        let object_info = ObjectInfo {
+            user_defined: Arc::new(
+                legacy_keys
+                    .iter()
+                    .map(|key| (key.to_string(), "2099-01-02T03:04:05Z".to_string()))
+                    .collect(),
+            ),
+            ..Default::default()
+        };
+
+        let (options, _) = replication_put_object_options("", &object_info).expect("build put options");
+
+        for legacy_key in legacy_keys {
+            assert!(!options.user_metadata.contains_key(legacy_key));
+            assert_eq!(
+                options
+                    .user_metadata
+                    .get(&format!("x-amz-meta-{legacy_key}"))
+                    .map(String::as_str),
+                Some("2099-01-02T03:04:05Z")
+            );
+        }
+        assert_eq!(options.internal.tagging_timestamp, OffsetDateTime::UNIX_EPOCH);
+        assert_eq!(options.internal.retention_timestamp, OffsetDateTime::UNIX_EPOCH);
+        assert_eq!(options.internal.legalhold_timestamp, OffsetDateTime::UNIX_EPOCH);
+    }
+
+    #[test]
+    fn replication_put_options_carry_retention_timestamp_after_clear() {
+        let mut metadata = HashMap::from([
+            (AMZ_OBJECT_LOCK_MODE.to_string(), String::new()),
+            (AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE.to_string(), String::new()),
+        ]);
+        rustfs_utils::http::insert_str(&mut metadata, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, "2026-01-02T03:04:05Z".to_string());
+        let object_info = ObjectInfo {
+            user_defined: Arc::new(metadata),
+            ..Default::default()
+        };
+
+        let (options, _) = replication_put_object_options("", &object_info).expect("retention clear must replicate");
+
+        assert!(options.mode.is_none());
+        assert_eq!(options.retain_until_date, OffsetDateTime::UNIX_EPOCH);
+        assert_eq!(
+            options.internal.retention_timestamp,
+            OffsetDateTime::parse("2026-01-02T03:04:05Z", &Rfc3339).expect("valid timestamp")
+        );
+        let headers = options.header();
+        assert!(!headers.contains_key(AMZ_OBJECT_LOCK_MODE));
+        assert!(!headers.contains_key(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE));
+        assert_eq!(
+            rustfs_utils::http::get_header(&headers, SUFFIX_SOURCE_REPLICATION_RETENTION_TIMESTAMP).as_deref(),
+            Some("2026-01-02T03:04:05Z")
+        );
+    }
+
    #[test]
    fn replication_put_options_strip_encryption_metadata_from_plaintext_objects() {
        use rustfs_utils::http::object_encryption_keys::{INTERNAL_ENCRYPTION_ORIGINAL_SIZE_HEADER, SSEC_ORIGINAL_SIZE_HEADER};
@@ -40,7 +40,14 @@ impl ARN {

 impl Display for ARN {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "arn:rustfs:{}:{}:{}:{}", self.arn_type, self.region, self.id, self.bucket)
+        // The `minio` partition is deliberate: madmin-go's ParseARN
+        // hard-rejects any other partition, so native mc/madmin tooling can
+        // only decode remote-target ARNs minted in this form (backlog#1675
+        // P1-7). Legacy `arn:rustfs:` ARNs persisted by older releases stay
+        // readable via the FromStr whitelist below; runtime matching between
+        // targets and replication rules is by full-string equality, so mixed
+        // partitions coexist safely.
+        write!(f, "arn:minio:{}:{}:{}:{}", self.arn_type, self.region, self.id, self.bucket)
    }
 }

@@ -48,7 +55,12 @@ impl FromStr for ARN {
    type Err = std::io::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        if !s.starts_with("arn:rustfs:") {
+        // Partition whitelist, not just an `arn:` check: `BucketTargetType::
+        // from_str(...).unwrap_or_default()` below never fails, so this is
+        // the only structural gate rejecting foreign ARNs. `arn:rustfs:` is
+        // the legacy partition and must stay accepted forever (persisted
+        // bucket-targets.json / replication configs from older releases).
+        if !s.starts_with("arn:minio:") && !s.starts_with("arn:rustfs:") {
            return Err(std::io::Error::new(std::io::ErrorKind::InvalidInput, "Invalid ARN format"));
        }

@@ -101,14 +113,50 @@ mod tests {
    }

    /// RustFS commonly generates ARNs with an empty region:
-    /// `arn:rustfs:replication::<deployment_id>:<bucket>`.
+    /// `arn:minio:replication::<deployment_id>:<bucket>`.
    #[test]
    fn from_str_handles_empty_region_segment() {
-        let parsed = ARN::from_str("arn:rustfs:replication::depl-123:bucket-a").expect("valid ARN must parse");
+        let parsed = ARN::from_str("arn:minio:replication::depl-123:bucket-a").expect("valid ARN must parse");

        assert_eq!(parsed.arn_type, BucketTargetType::ReplicationService);
        assert_eq!(parsed.region, "", "region segment is empty in this form");
        assert_eq!(parsed.id, "depl-123");
        assert_eq!(parsed.bucket, "bucket-a");
    }
+
+    /// madmin-go's `ParseARN` hard-rejects anything that does not start with
+    /// `arn:minio:`, so generated ARNs must use the `minio` partition or the
+    /// native mc/madmin tooling cannot decode remote-target listings.
+    #[test]
+    fn display_emits_minio_partition() {
+        let arn = ARN::new(
+            BucketTargetType::ReplicationService,
+            "depl-123".to_string(),
+            String::new(),
+            "bucket-a".to_string(),
+        );
+
+        assert_eq!(arn.to_string(), "arn:minio:replication::depl-123:bucket-a");
+    }
+
+    /// Persisted bucket-targets.json files from older RustFS releases carry
+    /// `arn:rustfs:` ARNs; the legacy partition must stay parseable forever.
+    #[test]
+    fn from_str_accepts_legacy_rustfs_partition() {
+        let parsed = ARN::from_str("arn:rustfs:replication:us-east-1:depl-123:bucket-a").expect("legacy ARN must parse");
+
+        assert_eq!(parsed.arn_type, BucketTargetType::ReplicationService);
+        assert_eq!(parsed.region, "us-east-1");
+        assert_eq!(parsed.id, "depl-123");
+        assert_eq!(parsed.bucket, "bucket-a");
+    }
+
+    /// The partition whitelist is the only structural gate: `BucketTargetType::
+    /// from_str(...).unwrap_or_default()` never fails, so any 6-segment string
+    /// would otherwise parse as `type=None`.
+    #[test]
+    fn from_str_rejects_unknown_partition() {
+        assert!(ARN::from_str("arn:aws:replication::depl-123:bucket-a").is_err());
+        assert!(ARN::from_str("not-an-arn").is_err());
+    }
 }
@@ -59,6 +59,10 @@ impl fmt::Debug for Credentials {
 }

 #[derive(Debug, Deserialize, Serialize, Default, Clone)]
+#[allow(
+    dead_code,
+    reason = "MinIO-parity bucket-target service discriminator with no caller in this port (backlog#1823)"
+)]
 pub enum ServiceType {
    #[default]
    Replication,
@@ -73,23 +73,6 @@ pub fn check_valid_bucket_name_strict(bucket_name: &str) -> Result<()> {
    check_bucket_name_common(bucket_name, true)
 }

-pub fn check_valid_object_name_prefix(object_name: &str) -> Result<()> {
-    if object_name.len() > 1024 {
-        return Err(Error::other("Object name cannot be longer than 1024 characters"));
-    }
-    if !object_name.is_ascii() {
-        return Err(Error::other("Object name with non-UTF-8 strings are not supported"));
-    }
-    Ok(())
-}
-
-pub fn check_valid_object_name(object_name: &str) -> Result<()> {
-    if object_name.trim().is_empty() {
-        return Err(Error::other("Object name cannot be empty"));
-    }
-    check_valid_object_name_prefix(object_name)
-}
-
 pub fn deserialize<T>(input: &[u8]) -> xml::DeResult<T>
 where
    T: for<'xml> xml::Deserialize<'xml>,
@@ -100,6 +83,10 @@ where
    Ok(ans)
 }

+#[allow(
+    dead_code,
+    reason = "xml serialize helper with no caller in this port; the live sibling is deserialize (backlog#1823)"
+)]
 pub fn serialize_content<T: xml::SerializeContent>(val: &T) -> xml::SerResult<String> {
    let mut buf = Vec::with_capacity(256);
    {
@@ -186,15 +173,27 @@ pub fn is_valid_object_name(object: &str) -> bool {
 /// Client-facing reason attached to rejections of object keys that Win32/NTFS
 /// cannot represent as file paths (issue #3299). Deployments on Linux/macOS
 /// accept the full S3 key character set.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub const WINDOWS_RESERVED_CHARACTERS_REASON: &str =
    "object key contains characters unsupported on Windows hosts (one of ':', '*', '?', '\"', '|', '<', '>')";

 /// Client-facing reason for path segments Windows can store but not address
 /// afterwards (issue #3449): trailing dot/space or reserved DOS device names.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub const WINDOWS_RESERVED_SEGMENT_REASON: &str = "object key contains a path segment unsupported on Windows hosts (trailing dot or space, or a reserved device name such as NUL/CON/COM1)";

 /// Reserved DOS device names that shadow regular files on Windows, even when
 /// an extension is appended (e.g. `NUL.txt` resolves to the `NUL` device).
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 const WINDOWS_RESERVED_NAMES: &[&str] = &[
    "CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2", "LPT3",
    "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
@@ -204,6 +203,10 @@ const WINDOWS_RESERVED_NAMES: &[&str] = &[
 /// the Win32 API cannot address afterwards (issue #3449): segments ending in a
 /// dot or a space, and reserved DOS device names — bare or with an extension
 /// (`NUL.txt`), matching classic Win32 path resolution semantics.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub fn object_name_has_windows_incompatible_segment(object: &str) -> bool {
    object.split(['/', '\\']).any(|segment| {
        if segment.ends_with('.') || segment.ends_with(' ') {
@@ -90,6 +90,10 @@ impl BucketVersioningSys {
    /// caller's own instance context so a second in-process store never
    /// answers with the first instance's versioning state; falls back to the
    /// ambient system when the instance cell is not initialized.
+    #[allow(
+        dead_code,
+        reason = "instance-scoped seam (backlog#1052) with no caller in this port (backlog#1823)"
+    )]
    pub(crate) async fn get_in(ctx: &crate::runtime::instance::InstanceContext, bucket: &str) -> Result<VersioningConfiguration> {
        if bucket == RUSTFS_META_BUCKET || bucket.starts_with(RUSTFS_META_BUCKET) {
            return Ok(VersioningConfiguration::default());
@@ -15,6 +15,7 @@
 use crate::disk::disk_store::{get_drive_walkdir_peek_timeout, get_drive_walkdir_stall_timeout};
 use crate::disk::error::DiskError;
 use crate::disk::{self, DiskAPI, DiskStore, WalkDirOptions};
+use futures::future::join_all;
 use metrics::counter;
 use rustfs_filemeta::{MetaCacheEntries, MetaCacheEntry, MetacacheReader, is_io_eof};
 use std::{
@@ -655,6 +656,7 @@ async fn list_path_raw_inner(
            errs.push(None);
        }
        let mut pending_entries: Vec<Option<MetaCacheEntry>> = vec![None; readers.len()];
+        let mut peek_outcomes: Vec<Option<PeekOutcome>> = std::iter::repeat_with(|| None).take(readers.len()).collect();

        loop {
            let mut current = MetaCacheEntry::default();
@@ -676,6 +678,21 @@ async fn list_path_raw_inner(
            let mut has_err = 0;
            let mut agree = 0;

+            // Start every missing head read in the same round so one stalled
+            // disk cannot multiply the wait budget by the erasure-set width.
+            // Outcomes are still consumed below in stable disk-index order.
+            let concurrent_peeks = readers.iter_mut().enumerate().filter_map(|(i, reader)| {
+                if errs[i].is_some() || pending_entries[i].is_some() {
+                    return None;
+                }
+
+                let cancel = &revjob_rx;
+                Some(async move { (i, peek_with_timeout(cancel, reader, peek_timeout).await) })
+            });
+            for (i, outcome) in join_all(concurrent_peeks).await {
+                peek_outcomes[i] = Some(outcome);
+            }
+
            for (i, r) in readers.iter_mut().enumerate() {
                if errs[i].is_some() {
                    has_err += 1;
@@ -685,7 +702,10 @@ async fn list_path_raw_inner(
                let entry = if let Some(entry) = pending_entries[i].take() {
                    entry
                } else {
-                    match peek_with_timeout(&revjob_rx, r, peek_timeout).await {
+                    let Some(outcome) = peek_outcomes[i].take() else {
+                        return Err(DiskError::Unexpected);
+                    };
+                    match outcome {
                        PeekOutcome::Ready(res) => {
                            if let Some(entry) = res {
                                // info!("read entry disk: {}, name: {}", i, entry.name);
@@ -1295,6 +1315,36 @@ mod tests {
        assert_eq!(err, DiskError::Timeout);
    }

+    #[tokio::test(start_paused = true)]
+    async fn list_path_raw_bounds_multiple_stalled_readers_by_one_peek_deadline() {
+        let peek_timeout = Duration::from_millis(20);
+        let started = tokio::time::Instant::now();
+        let err = list_path_raw(
+            CancellationToken::new(),
+            ListPathRawOptions {
+                disks: vec![None, None, None, None],
+                min_disks: 1,
+                test_reader_behaviors: vec![
+                    TestReaderBehavior::Stall,
+                    TestReaderBehavior::Stall,
+                    TestReaderBehavior::Stall,
+                    TestReaderBehavior::Stall,
+                ],
+                peek_timeout: Some(peek_timeout),
+                ..Default::default()
+            },
+        )
+        .await
+        .expect_err("all stalled readers should fail the listing");
+
+        assert_eq!(err, DiskError::Timeout);
+        assert_eq!(
+            started.elapsed(),
+            peek_timeout,
+            "reader deadlines must overlap instead of accumulating once per disk"
+        );
+    }
+
    #[tokio::test]
    async fn list_path_raw_waits_past_producer_stall_for_slow_progressing_reader() {
        let entry = MetaCacheEntry {
@@ -229,17 +229,6 @@ pub fn http_resp_to_error_response(
    err_resp
 }

-pub fn err_transfer_acceleration_bucket(bucket_name: &str) -> ErrorResponse {
-    ErrorResponse {
-        status_code: StatusCode::BAD_REQUEST,
-        code: S3ErrorCode::InvalidArgument,
-        message: "The name of the bucket used for Transfer Acceleration must be DNS-compliant and must not contain periods ‘.’."
-            .to_string(),
-        bucket_name: bucket_name.to_string(),
-        ..Default::default()
-    }
-}
-
 pub fn err_entity_too_large(total_size: i64, max_object_size: i64, bucket_name: &str, object_name: &str) -> ErrorResponse {
    let msg = format!(
        "Your proposed upload size ‘{}’ exceeds the maximum allowed object size ‘{}’ for single PUT operation.",
@@ -295,16 +284,6 @@ pub fn err_invalid_argument(message: &str) -> ErrorResponse {
    }
 }

-pub fn err_api_not_supported(message: &str) -> ErrorResponse {
-    ErrorResponse {
-        status_code: StatusCode::NOT_IMPLEMENTED,
-        code: S3ErrorCode::Custom("APINotSupported".into()),
-        message: message.to_string(),
-        request_id: "rustfs".to_string(),
-        ..Default::default()
-    }
-}
-
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -95,7 +95,6 @@ impl TransitionClient {
 }

 #[derive(Default)]
-#[allow(dead_code)]
 pub struct GetRequest {
    pub buffer: Vec<u8>,
    pub offset: i64,
@@ -107,11 +106,12 @@ pub struct GetRequest {
    pub setting_object_info: bool,
 }

-#[allow(dead_code)]
 pub struct GetResponse {
    pub size: i64,
    //pub error:       error,
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    pub did_read: bool,
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    pub object_info: ObjectInfo,
 }

@@ -135,6 +135,10 @@ impl Object {
        Self { ..Default::default() }
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity reader surface with no caller in this port (backlog#1823)"
+    )]
    fn do_get_request(&self, request: &GetRequest) -> Result<GetResponse, std::io::Error> {
        let _ = request.did_offset_change;
        let _ = request.offset;
@@ -150,12 +154,20 @@ impl Object {
        ))
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn set_offset(&mut self, bytes_read: i64) -> Result<(), std::io::Error> {
        self.curr_offset += bytes_read;

        Ok(())
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn read(&mut self, b: &[u8]) -> Result<i64, std::io::Error> {
        let mut read_req = GetRequest {
            is_read_op: true,
@@ -180,6 +192,10 @@ impl Object {
        Ok(response.size)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn stat(&self) -> Result<ObjectInfo, std::io::Error> {
        if !self.is_started || !self.object_info_set {
            let _ = self.do_get_request(&GetRequest {
@@ -192,6 +208,10 @@ impl Object {
        Ok(self.object_info.clone())
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn read_at(&mut self, b: &[u8], offset: i64) -> Result<i64, std::io::Error> {
        self.curr_offset = offset;

@@ -219,6 +239,10 @@ impl Object {
        Ok(response.size)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn seek(&mut self, offset: i64, whence: i64) -> Result<i64, std::io::Error> {
        if !self.is_started || !self.object_info_set {
            let seek_req = GetRequest {
@@ -253,6 +277,10 @@ impl Object {
        Ok(self.curr_offset)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity Object reader method with no caller in this port (backlog#1823)"
+    )]
    fn close(&mut self) -> Result<(), std::io::Error> {
        self.is_closed = true;
        Ok(())
@@ -20,6 +20,7 @@
 #![allow(clippy::all)]

 use http::{HeaderMap, HeaderName, HeaderValue};
+use rustfs_utils::http::headers::AMZ_CHECKSUM_MODE;
 use std::collections::HashMap;
 use time::OffsetDateTime;
 use tracing::warn;
@@ -27,7 +28,6 @@ use tracing::warn;
 use crate::client::api_error_response::err_invalid_argument;

 #[derive(Default)]
-#[allow(dead_code)]
 pub struct AdvancedGetOptions {
    pub replication_delete_marker: bool,
    pub is_replication_ready_for_delete_marker: bool,
@@ -77,7 +77,7 @@ impl GetObjectOptions {
            }
        }
        if self.checksum {
-            headers.insert(HeaderName::from_static("x-amz-checksum-mode"), HeaderValue::from_static("ENABLED"));
+            headers.insert(HeaderName::from_static(AMZ_CHECKSUM_MODE), HeaderValue::from_static("ENABLED"));
        }
        headers
    }
@@ -360,7 +360,6 @@ impl TransitionClient {
 }

 #[derive(Default)]
-#[allow(dead_code)]
 pub struct ListObjectsOptions {
    reverse_versions: bool,
    with_versions: bool,
@@ -37,7 +37,7 @@ use crate::client::{
    api_put_object_common::optimal_part_info,
    api_put_object_multipart::UploadPartParams,
    api_s3_datatypes::{CompleteMultipartUpload, CompletePart, ObjectPart},
-    constants::{ISO8601_DATEFORMAT, MAX_MULTIPART_PUT_OBJECT_SIZE, MIN_PART_SIZE, TOTAL_WORKERS},
+    constants::{ISO8601_DATEFORMAT, MAX_MULTIPART_PUT_OBJECT_SIZE, MIN_PART_SIZE},
    credentials::SignatureType,
    transition_api::{ReaderImpl, TransitionClient, UploadInfo},
    utils::{is_amz_header, is_minio_header, is_rustfs_header, is_standard_header, is_storageclass_header},
@@ -137,8 +137,8 @@ impl Default for PutObjectOptions {
    }
 }

-#[allow(dead_code)]
 impl PutObjectOptions {
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn set_match_etag(&mut self, etag: &str) {
        if etag == "*" {
            self.custom_header.insert("If-Match", HeaderValue::from_static("*"));
@@ -149,6 +149,7 @@ impl PutObjectOptions {
        }
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn set_match_etag_except(&mut self, etag: &str) {
        if etag == "*" {
            self.custom_header.insert("If-None-Match", HeaderValue::from_static("*"));
@@ -259,6 +260,7 @@ impl PutObjectOptions {
        header
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn validate(&self, c: TransitionClient) -> Result<(), std::io::Error> {
        //if self.checksum.is_set() {
        /*if !self.trailing_header_support {
@@ -30,10 +30,6 @@ pub fn is_object(reader: &ReaderImpl) -> bool {
    matches!(reader, ReaderImpl::ObjectBody(_))
 }

-pub fn is_read_at(reader: ReaderImpl) -> bool {
-    matches!(reader, ReaderImpl::ObjectBody(_))
-}
-
 pub fn optimal_part_info(object_size: i64, configured_part_size: u64) -> Result<(i64, i64, i64), std::io::Error> {
    let unknown_size;
    let mut object_size = object_size;
@@ -81,18 +81,6 @@ async fn read_multipart_part(reader: &mut ReaderImpl, want: usize) -> Result<Vec
    }
 }

-pub struct UploadedPartRes {
-    pub error: std::io::Error,
-    pub part_num: i64,
-    pub size: i64,
-    pub part: ObjectPart,
-}
-
-pub struct UploadPartReq {
-    pub part_num: i64,
-    pub part: ObjectPart,
-}
-
 impl TransitionClient {
    pub async fn put_object_multipart_stream(
        self: Arc<Self>,
@@ -55,7 +55,6 @@ pub struct RemoveBucketOptions {
 const DELETE_RESPONSE_PREVIEW_LEN: usize = 1024;

 #[derive(Debug)]
-#[allow(dead_code)]
 pub struct AdvancedRemoveOptions {
    pub replication_delete_marker: bool,
    pub replication_status: ReplicationStatus,
@@ -465,10 +464,10 @@ impl TransitionClient {
 }

 #[derive(Debug, Default)]
-#[allow(dead_code)]
 pub struct RemoveObjectError {
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    object_name: String,
-    #[allow(dead_code)]
+    #[allow(dead_code, reason = "written but never read back (backlog#1823)")]
    version_id: String,
    err: Option<std::io::Error>,
 }
@@ -29,10 +29,6 @@ use crate::client::utils::base64_decode;

 use super::transition_api;

-pub struct ListAllMyBucketsResult {
-    pub owner: Owner,
-}
-
 #[derive(Debug, Default, Serialize, Deserialize)]
 pub struct CommonPrefix {
    pub prefix: String,
@@ -89,6 +85,10 @@ pub struct ListVersionsResult {
    pub next_version_id_marker: String,
 }

+#[allow(
+    dead_code,
+    reason = "fields of a MinIO-parity list result that this port builds but never reads back (backlog#1823)"
+)]
 pub struct ListBucketResult {
    common_prefixes: Vec<CommonPrefix>,
    contents: Vec<transition_api::ObjectInfo>,
@@ -102,6 +102,10 @@ pub struct ListBucketResult {
    prefix: String,
 }

+#[allow(
+    dead_code,
+    reason = "fields of a MinIO-parity list result that this port builds but never reads back (backlog#1823)"
+)]
 pub struct ListMultipartUploadsResult {
    bucket: String,
    key_marker: String,
@@ -117,16 +121,15 @@ pub struct ListMultipartUploadsResult {
    common_prefixes: Vec<CommonPrefix>,
 }

+#[allow(
+    dead_code,
+    reason = "fields of a MinIO-parity list result that this port builds but never reads back (backlog#1823)"
+)]
 pub struct Initiator {
    id: String,
    display_name: String,
 }

-pub struct CopyObjectResult {
-    pub etag: String,
-    pub last_modified: OffsetDateTime,
-}
-
 #[derive(Debug, Clone)]
 pub struct ObjectPart {
    pub etag: String,
@@ -260,6 +263,7 @@ pub struct CompletePart {
 }

 impl CompletePart {
+    #[allow(dead_code, reason = "MinIO-parity accessor with no caller in this port (backlog#1823)")]
    fn checksum(&self, t: &ChecksumMode) -> String {
        match t {
            ChecksumMode::ChecksumCRC32C => {
@@ -284,11 +288,6 @@ impl CompletePart {
    }
 }

-pub struct CopyObjectPartResult {
-    pub etag: String,
-    pub last_modified: OffsetDateTime,
-}
-
 #[derive(Debug, Default, serde::Serialize)]
 #[serde(rename = "CompleteMultipartUpload")]
 pub struct CompleteMultipartUpload {
@@ -357,10 +356,10 @@ impl CompleteMultipartUpload {
    }
 }

-pub struct CreateBucketConfiguration {
-    pub location: String,
-}
-
+#[allow(
+    dead_code,
+    reason = "live via quick_xml::de::from_str in bucket_cache.rs; serde deserialization is not a construction (backlog#1823)"
+)]
 #[derive(serde::Serialize)]
 pub struct DeleteObject {
    //api has
@@ -368,21 +367,6 @@ pub struct DeleteObject {
    pub version_id: String,
 }

-pub struct DeletedObject {
-    //s3s has
-    pub key: String,
-    pub version_id: String,
-    pub deletemarker: bool,
-    pub deletemarker_version_id: String,
-}
-
-pub struct NonDeletedObject {
-    pub key: String,
-    pub code: String,
-    pub message: String,
-    pub version_id: String,
-}
-
 #[derive(serde::Serialize)]
 pub struct DeleteMultiObjects {
    pub quiet: bool,
@@ -402,6 +386,7 @@ impl DeleteMultiObjects {
        Ok(buf)
    }

+    #[allow(dead_code, reason = "MinIO-parity XML helper with no caller in this port (backlog#1823)")]
    pub fn unmarshal(buf: &[u8]) -> Result<Self, std::io::Error> {
        #[derive(Debug, Deserialize)]
        struct WireDeleteObject {
@@ -436,8 +421,3 @@ impl DeleteMultiObjects {
        })
    }
 }
-
-pub struct DeleteMultiObjectsResult {
-    pub deleted_objects: Vec<DeletedObject>,
-    pub undeleted_objects: Vec<NonDeletedObject>,
-}
@@ -365,11 +365,15 @@ mod tests {
 pub struct Checksum {
    checksum_type: ChecksumMode,
    r: Vec<u8>,
+    #[allow(
+        dead_code,
+        reason = "checksum bookkeeping field kept beside the value it guards (backlog#1823)"
+    )]
    computed: bool,
 }

-#[allow(dead_code)]
 impl Checksum {
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn new(t: ChecksumMode, b: &[u8]) -> Checksum {
        if t.is_set() && b.len() == t.raw_byte_len() {
            return Checksum {
@@ -381,7 +385,7 @@ impl Checksum {
        Checksum::default()
    }

-    #[allow(dead_code)]
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn new_checksum_string(t: ChecksumMode, s: &str) -> Result<Checksum, std::io::Error> {
        let b = match base64_decode(s.as_bytes()) {
            Ok(b) => b,
@@ -408,7 +412,7 @@ impl Checksum {
        base64_encode(&self.r)
    }

-    #[allow(dead_code)]
+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn raw(&self) -> Option<Vec<u8>> {
        if !self.is_set() {
            return None;
@@ -32,8 +32,5 @@ pub const MAX_MULTIPART_PUT_OBJECT_SIZE: i64 = 1024 * 1024 * 1024 * 1024 * 5;
 pub const UNSIGNED_PAYLOAD: &str = "UNSIGNED-PAYLOAD";
 pub const UNSIGNED_PAYLOAD_TRAILER: &str = "STREAMING-UNSIGNED-PAYLOAD-TRAILER";

-pub const TOTAL_WORKERS: i64 = 4;
-
-pub const SIGN_V4_ALGORITHM: &str = "AWS4-HMAC-SHA256";
 pub const ISO8601_DATEFORMAT: &[FormatItem<'_>] =
    format_description!("[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond]Z");
@@ -67,6 +67,10 @@ impl<P: Provider + Default> Credentials<P> {
        Ok(self.creds.clone())
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity credential surface with no caller in this port (backlog#1823)"
+    )]
    fn expire(&mut self) {
        self.force_refresh = true;
    }
@@ -133,6 +137,10 @@ impl Provider for Static {

 #[derive(Debug, Clone, Default)]
 pub struct STSError {
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity STS error detail that this port never reads back (backlog#1823)"
+    )]
    pub r#type: String,
    pub code: String,
    pub message: String,
@@ -141,6 +149,10 @@ pub struct STSError {
 #[derive(Debug, Clone, thiserror::Error)]
 pub struct ErrorResponse {
    pub sts_error: STSError,
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity STS error detail that this port never reads back (backlog#1823)"
+    )]
    pub request_id: String,
 }

@@ -158,22 +170,3 @@ impl ErrorResponse {
        return self.sts_error.message.clone();
    }
 }
-
-pub fn xml_decoder<T>(body: &[u8]) -> Result<T, Error>
-where
-    for<'de> T: Deserialize<'de>,
-{
-    match std::str::from_utf8(body) {
-        Ok(xml_body) => quick_xml::de::from_str::<T>(xml_body).map_err(|err| Error::new(ErrorKind::InvalidData, err.to_string())),
-        Err(err) => Err(Error::new(ErrorKind::InvalidData, err.to_string())),
-    }
-}
-
-pub fn xml_decode_and_body<T>(body_reader: &[u8]) -> Result<(Vec<u8>, T), std::io::Error>
-where
-    for<'de> T: Deserialize<'de>,
-{
-    let body = body_reader.to_vec();
-    let parsed = xml_decoder(&body)?;
-    Ok((body, parsed))
-}
@@ -13,7 +13,6 @@
 // limitations under the License.

 // #730: S3 client compatibility models are kept while ECStore callers move to narrower facades.
-#![allow(dead_code)]

 pub mod admin_handler_utils;
 pub mod api_error_response;
@@ -37,16 +37,17 @@ pub struct PutObjReader {
    //pub sealMD5Fn: SealMD5CurrFn,
 }

-#[allow(dead_code)]
 impl PutObjReader {
    pub fn new(reader: HashReader) -> Self {
        Self { reader }
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn md5_current_hex_string(&self) -> String {
        self.reader.checksum().map(|v| v.encoded).unwrap_or_default()
    }

+    #[allow(dead_code, reason = "MinIO-parity surface with no caller in this port (backlog#1823)")]
    fn with_encryption(&mut self, enc_reader: HashReader) -> Result<(), std::io::Error> {
        self.reader = enc_reader;

@@ -77,39 +78,6 @@ fn part_number_to_rangespec(oi: ObjectInfo, part_number: usize) -> Option<HTTPRa
    })
 }

-fn get_compressed_offsets(oi: ObjectInfo, offset: i64) -> (i64, i64, i64, i64, u64) {
-    let mut skip_length: i64 = 0;
-    let mut cumulative_actual_size: i64 = 0;
-    let mut first_part_idx: i64 = 0;
-    let mut compressed_offset: i64 = 0;
-    let mut part_skip: i64 = 0;
-    let mut decrypt_skip: i64 = 0;
-    let mut seq_num: u64 = 0;
-    for (i, part) in oi.parts.iter().enumerate() {
-        cumulative_actual_size += part.actual_size as i64;
-        if cumulative_actual_size <= offset {
-            compressed_offset += part.size as i64;
-        } else {
-            first_part_idx = i as i64;
-            skip_length = cumulative_actual_size - part.actual_size as i64;
-            break;
-        }
-    }
-    skip_length = offset - skip_length;
-
-    let parts: &[ObjectPartInfo] = &oi.parts;
-    if skip_length > 0
-        && parts.len() > first_part_idx as usize
-        && parts[first_part_idx as usize].index.as_ref().is_some_and(|idx| idx.len() > 0)
-    {
-        let _ = part_skip;
-        let _ = decrypt_skip;
-        let _ = seq_num;
-    }
-
-    (compressed_offset, part_skip, first_part_idx, decrypt_skip, seq_num)
-}
-
 pub fn new_getobjectreader<'a>(
    rs: &Option<HTTPRangeSpec>,
    oi: &'a ObjectInfo,
@@ -23,6 +23,7 @@ const X_OBS_VERSION_ID: &str = "x-obs-version-id";
 const MAX_REMOTE_VERSION_ID_LEN: usize = 1024;

 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[allow(dead_code, reason = "bucket versioning states kept as a complete vocabulary (backlog#1823)")]
 pub(crate) enum BucketVersioningState {
    Unknown,
    Disabled,
@@ -47,6 +48,7 @@ impl RemoteVersion {
        }
    }

+    #[allow(dead_code, reason = "MinIO-parity accessor with no caller in this port (backlog#1823)")]
    pub(crate) fn exact_request_id(&self) -> Result<Option<&str>, Error> {
        match self {
            Self::Unknown => Err(Error::new(
@@ -54,6 +54,10 @@ use rustfs_config::MAX_S3_CLIENT_RESPONSE_SIZE;
 use rustfs_rio::HashReader;
 use rustfs_utils::HashAlgorithm;
 use rustfs_utils::{
+    http::headers::{
+        AMZ_CHECKSUM_CRC32, AMZ_CHECKSUM_CRC32C, AMZ_CHECKSUM_CRC64NVME, AMZ_CHECKSUM_MODE, AMZ_CHECKSUM_SHA1,
+        AMZ_CHECKSUM_SHA256,
+    },
    net::get_endpoint_url,
    retry::{DEFAULT_RETRY_CAP, DEFAULT_RETRY_UNIT, MAX_JITTER, MAX_RETRY, RetryTimer},
 };
@@ -101,6 +105,10 @@ where

 const C_UNKNOWN: i32 = -1;
 const C_OFFLINE: i32 = 0;
+#[allow(
+    dead_code,
+    reason = "reachable only from the unused transition client methods below (backlog#1823)"
+)]
 const C_ONLINE: i32 = 1;

 fn invalid_utf8_header_error(scope: &str, header_name: &str) -> std::io::Error {
@@ -320,6 +328,10 @@ impl TransitionClient {
        Ok(client)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client surface with no caller in this port (backlog#1823)"
+    )]
    fn endpoint_url(&self) -> Url {
        self.endpoint_url.clone()
    }
@@ -348,12 +360,20 @@ impl TransitionClient {
            .to_string())
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn trace_errors_only_off(&self) {
        if let Ok(mut trace_errors_only) = self.trace_errors_only.lock() {
            *trace_errors_only = false;
        }
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn trace_off(&self) {
        if let Ok(mut is_trace_enabled) = self.is_trace_enabled.lock() {
            *is_trace_enabled = false;
@@ -363,12 +383,20 @@ impl TransitionClient {
        }
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn set_s3_transfer_accelerate(&self, accelerate_endpoint: &str) {
        if let Ok(mut endpoint) = self.s3_accelerate_endpoint.lock() {
            *endpoint = accelerate_endpoint.to_string();
        }
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn set_s3_enable_dual_stack(&self, enabled: bool) {
        if let Ok(mut dual_stack) = self.s3_dual_stack_enabled.lock() {
            *dual_stack = enabled;
@@ -398,10 +426,18 @@ impl TransitionClient {
        (hash_algos, hash_sums)
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn is_online(&self) -> bool {
        !self.is_offline()
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn mark_offline(&self) {
        self.health_status
            .compare_exchange(C_ONLINE, C_OFFLINE, Ordering::SeqCst, Ordering::SeqCst);
@@ -411,10 +447,18 @@ impl TransitionClient {
        self.health_status.load(Ordering::SeqCst) == C_OFFLINE
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn health_check(hc_duration: Duration) {
        let _ = hc_duration;
    }

+    #[allow(
+        dead_code,
+        reason = "MinIO-parity transition client method with no caller in this port (backlog#1823)"
+    )]
    fn dump_http(&self, req: &Request<s3s::Body>, resp: &Response<Incoming>) -> Result<(), std::io::Error> {
        let mut resp_trace: Vec<u8>;

@@ -1102,6 +1146,7 @@ impl Default for ObjectInfo {
 }

 impl ObjectInfo {
+    #[allow(dead_code, reason = "MinIO-parity accessor with no caller in this port (backlog#1823)")]
    pub(crate) fn remote_version(
        &self,
        capabilities: ProviderVersionCapabilities,
@@ -1342,12 +1387,12 @@ pub(crate) fn to_object_info_for_provider(
    };

    // Extract checksums
-    let checksum_crc32 = get_header("x-amz-checksum-crc32");
-    let checksum_crc32c = get_header("x-amz-checksum-crc32c");
-    let checksum_sha1 = get_header("x-amz-checksum-sha1");
-    let checksum_sha256 = get_header("x-amz-checksum-sha256");
-    let checksum_crc64nvme = get_header("x-amz-checksum-crc64nvme");
-    let checksum_mode = get_header("x-amz-checksum-mode");
+    let checksum_crc32 = get_header(AMZ_CHECKSUM_CRC32);
+    let checksum_crc32c = get_header(AMZ_CHECKSUM_CRC32C);
+    let checksum_sha1 = get_header(AMZ_CHECKSUM_SHA1);
+    let checksum_sha256 = get_header(AMZ_CHECKSUM_SHA256);
+    let checksum_crc64nvme = get_header(AMZ_CHECKSUM_CRC64NVME);
+    let checksum_mode = get_header(AMZ_CHECKSUM_MODE);

    // Build and return the ObjectInfo struct
    Ok(ObjectInfo {
@@ -48,10 +48,6 @@ lazy_static! {
    };
 }

-pub fn is_standard_query_value(qs_key: &str) -> bool {
-    SUPPORTED_QUERY_VALUES[qs_key]
-}
-
 pub fn is_storageclass_header(header_key: &str) -> bool {
    header_key.to_lowercase() == X_AMZ_STORAGE_CLASS.as_str().to_lowercase()
 }
@@ -13,7 +13,6 @@
 // limitations under the License.

 // #730: cluster/RPC migration leaves transport capabilities staged for upcoming owners.
-#![allow(dead_code)]

 mod control_plane;
 pub(crate) mod rpc;
@@ -256,6 +256,7 @@ impl<S> ReplayScopeChannel<S> {
    }
 }

+#[allow(dead_code, reason = "replay-state probe asserted by this file's tests (backlog#1823)")]
 fn peer_replay_state(audience: &str) -> PeerReplayState {
    PEER_REPLAY_STATES
        .lock()
@@ -31,7 +31,7 @@ use rustfs_config::{
    DEFAULT_INTERNODE_DATA_TRANSPORT, ENV_RUSTFS_INTERNODE_DATA_TRANSPORT, INTERNODE_DATA_TRANSPORT_TCP,
    KNOWN_INTERNODE_DATA_TRANSPORT_BACKENDS,
 };
-use rustfs_rio::{HttpReader, HttpWriter};
+use rustfs_rio::{ChunkReaderBox, HttpChunkReader, HttpReader, HttpWriter};
 use sha2::{Digest, Sha256};
 use std::collections::HashMap;
 use std::future::Future;
@@ -43,6 +43,10 @@ use tokio::io::{AsyncReadExt, AsyncWrite};
 use tokio::sync::OnceCell;
 use uuid::Uuid;

+#[allow(
+    dead_code,
+    reason = "live in the cfg(not(test)) half of build_internode_data_transport_from_env (backlog#1823)"
+)]
 static INTERNODE_DATA_TRANSPORT: OnceLock<std::result::Result<Arc<dyn InternodeDataTransport>, String>> = OnceLock::new();

 const READ_FILE_STREAM_PATH: &str = "/rustfs/rpc/read_file_stream";
@@ -134,6 +138,10 @@ fn put_file_capability_status_is_legacy(status: u16) -> bool {
 }

 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
+#[allow(
+    dead_code,
+    reason = "capability-negotiation seam; constructed only by transport test doubles (backlog#1823)"
+)]
 pub struct InternodeDataTransportCapabilities {
    /// Backend can open a streaming remote disk reader.
    pub streaming_read: bool,
@@ -150,6 +158,10 @@ pub struct InternodeDataTransportCapabilities {
 }

 impl InternodeDataTransportCapabilities {
+    #[allow(
+        dead_code,
+        reason = "capability-negotiation seam; used by transport test doubles (backlog#1823)"
+    )]
    pub const fn tcp_http() -> Self {
        Self {
            streaming_read: true,
@@ -221,6 +233,17 @@ pub struct NsScannerCapabilityRequest {
 #[async_trait]
 pub trait InternodeDataTransport: Send + Sync + std::fmt::Debug {
    async fn open_read(&self, request: ReadStreamRequest) -> Result<FileReader>;
+    async fn open_read_fresh(&self, request: ReadStreamRequest) -> Result<FileReader> {
+        self.open_read(request).await
+    }
+    /// Opens an owned-chunk stream when this transport can retain receive-buffer
+    /// ownership. `None` preserves the established `open_read` fallback.
+    async fn open_read_chunks(&self, _request: ReadStreamRequest) -> Result<Option<ChunkReaderBox>> {
+        Ok(None)
+    }
+    async fn open_read_chunks_fresh(&self, request: ReadStreamRequest) -> Result<Option<ChunkReaderBox>> {
+        self.open_read_chunks(request).await
+    }
    async fn open_write(&self, request: WriteStreamRequest) -> Result<FileWriter>;
    async fn open_walk_dir(&self, request: WalkDirStreamRequest) -> Result<FileReader>;
    async fn open_ns_scanner(&self, _request: NsScannerStreamRequest) -> Result<FileReader> {
@@ -229,7 +252,12 @@ pub trait InternodeDataTransport: Send + Sync + std::fmt::Debug {
    async fn probe_ns_scanner(&self, _request: NsScannerCapabilityRequest) -> Result<Uuid> {
        Err(Error::MethodNotAllowed)
    }
+    // Interface facet nobody calls yet: every transport implements both, but no
+    // caller negotiates on them. Kept for the internode transport split
+    // (backlog#1350); deleting them would delete the seam and six impls.
+    #[allow(dead_code, reason = "unused capability-negotiation facet (backlog#1823)")]
    fn name(&self) -> &'static str;
+    #[allow(dead_code, reason = "unused capability-negotiation facet (backlog#1823)")]
    fn capabilities(&self) -> InternodeDataTransportCapabilities;
 }

@@ -247,6 +275,34 @@ impl InternodeDataTransport for TcpHttpInternodeDataTransport {
        ))
    }

+    async fn open_read_fresh(&self, request: ReadStreamRequest) -> Result<FileReader> {
+        let url = build_read_file_stream_url(&request);
+        let mut headers = json_headers();
+        build_auth_headers(&url, &Method::GET, &mut headers)?;
+        Ok(Box::new(
+            HttpReader::new_fresh_connection_with_stall_timeout(url, Method::GET, headers, None, request.stall_timeout).await?,
+        ))
+    }
+
+    async fn open_read_chunks(&self, request: ReadStreamRequest) -> Result<Option<ChunkReaderBox>> {
+        let url = build_read_file_stream_url(&request);
+        let mut headers = json_headers();
+        build_auth_headers(&url, &Method::GET, &mut headers)?;
+        Ok(Some(Box::new(
+            HttpChunkReader::new_with_stall_timeout(url, Method::GET, headers, None, request.stall_timeout).await?,
+        )))
+    }
+
+    async fn open_read_chunks_fresh(&self, request: ReadStreamRequest) -> Result<Option<ChunkReaderBox>> {
+        let url = build_read_file_stream_url(&request);
+        let mut headers = json_headers();
+        build_auth_headers(&url, &Method::GET, &mut headers)?;
+        Ok(Some(Box::new(
+            HttpChunkReader::new_fresh_connection_with_stall_timeout(url, Method::GET, headers, None, request.stall_timeout)
+                .await?,
+        )))
+    }
+
    async fn open_write(&self, request: WriteStreamRequest) -> Result<FileWriter> {
        let server_epoch = self.put_file_auth_capability(&request.endpoint).await?;
        let nonce = server_epoch.map(|_| Uuid::new_v4());
@@ -656,6 +712,10 @@ fn build_internode_data_transport_result(
    }
 }

+#[allow(
+    dead_code,
+    reason = "live in the cfg(test) half of build_internode_data_transport_from_env, which bypasses the process static (backlog#1823)"
+)]
 pub fn build_internode_data_transport(configured_transport: Option<&str>) -> Result<Arc<dyn InternodeDataTransport>> {
    build_internode_data_transport_result(configured_transport).map_err(Error::other)
 }
@@ -86,6 +86,25 @@ const PEER_REST_RECOVERY_MAX_BACKOFF: Duration = Duration::from_secs(30);
 const SCANNER_ACTIVITY_MAX_MESSAGE_SIZE: usize = 1024;
 const REPLICATION_STATS_MAX_MESSAGE_SIZE: usize = 8 * 1024 * 1024;

+/// Error for a peer that reported `success = false` without an `error_info` payload.
+///
+/// Same shape as `peer_s3_client::peer_failure_without_details`, over `StorageError`
+/// instead of `DiskError`. The message names the operation (and the bucket, where the
+/// operation has one) and nothing else, for two reasons:
+///
+/// - `finalize_result` classifies failures by message substring, so any text matching
+///   `message_has_network_needle` would take an answering peer offline and evict its
+///   connection over a plain application-level rejection.
+/// - Quorum aggregation (`reduce_errs`) buckets `Io` errors by kind plus rendered
+///   message, so a per-peer detail such as the peer address would split one shared
+///   failure into single-count buckets and downgrade the dominant error.
+fn peer_failure_without_details(op: &str, bucket: Option<&str>) -> Error {
+    match bucket {
+        Some(bucket) => Error::other(format!("{op}({bucket}): peer returned failure without error details")),
+        None => Error::other(format!("{op}: peer returned failure without error details")),
+    }
+}
+
 fn decode_bucket_stats_response(response: GetBucketStatsDataResponse) -> Result<BucketStats> {
    if !response.success {
        return Err(Error::other(
@@ -248,6 +267,16 @@ fn decode_remote_version_state_capability(expected_member: &str, result: &[u8])
    Ok(server_epoch)
 }

+fn decode_cross_pool_fence_capability(expected_member: &str, result: &[u8]) -> Result<(u32, Uuid)> {
+    let version = result
+        .get(..4)
+        .and_then(|value| value.try_into().ok())
+        .map(u32::from_be_bytes)
+        .ok_or_else(|| Error::other("peer returned an invalid cross-pool fence capability version"))?;
+    let epoch = decode_remote_version_state_capability(expected_member, &result[4..])?;
+    Ok((version, epoch))
+}
+
 #[derive(Clone, Debug)]
 pub struct PeerLiveEventsBatch {
    pub events: Vec<u8>,
@@ -686,7 +715,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("local_storage_info", None));
        }
        let data = response.storage_info;

@@ -709,7 +738,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("server_info", None));
        }
        let data = response.server_properties;

@@ -732,7 +761,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("get_cpus", None));
        }
        let data = response.cpus;

@@ -755,7 +784,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("get_net_info", None));
        }
        let data = response.net_info;

@@ -778,7 +807,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("get_partitions", None));
        }
        let data = response.partitions;

@@ -801,7 +830,7 @@ impl PeerRestClient {
            if let Some(msg) = response.error_info {
                return Err(Error::other(msg));
            }
-            return Err(Error::other(""));
+            return Err(peer_failure_without_details("get_os_info", None));
        }
        let data = response.os_info;

@@ -822,7 +851,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_se_linux_info", None));
                }
                let data = response.sys_services;

@@ -847,7 +876,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_sys_config", None));
                }
                let data = response.sys_config;

@@ -872,7 +901,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_sys_errors", None));
                }
                let data = response.sys_errors;

@@ -897,7 +926,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_mem_info", None));
                }
                let data = response.mem_info;

@@ -929,7 +958,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_metrics", None));
                }
                let data = response.realtime_metrics;

@@ -954,7 +983,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_live_events", None));
                }

                Ok(PeerLiveEventsBatch {
@@ -979,7 +1008,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("get_proc_info", None));
                }
                let data = response.proc_info;

@@ -1006,7 +1035,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("start_profiling", None));
                }
                Ok(())
            }
@@ -1288,6 +1317,16 @@ impl PeerRestClient {
        Ok((self.topology_member.clone(), epoch))
    }

+    pub async fn probe_cross_pool_fence(&self, topology_fingerprint: String) -> Result<(String, u32, Uuid)> {
+        let mut probe = rustfs_protos::CROSS_POOL_FENCE_CAPABILITY_PROBE_PREFIX.to_vec();
+        probe.extend_from_slice(Uuid::new_v4().as_bytes());
+        let result = self
+            .heal_control(rustfs_protos::HEAL_CONTROL_PROTOCOL_VERSION, topology_fingerprint, probe)
+            .await?;
+        let (supported_version, epoch) = decode_cross_pool_fence_capability(&self.topology_member, &result)?;
+        Ok((self.topology_member.clone(), supported_version, epoch))
+    }
+
    pub async fn load_bucket_metadata(&self, bucket: &str, scanner_maintenance_change: bool) -> Result<()> {
        self.finalize_result(
            async {
@@ -1303,7 +1342,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_bucket_metadata", Some(bucket)));
                }
                Ok(())
            }
@@ -1326,7 +1365,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("delete_bucket_metadata", Some(bucket)));
                }
                Ok(())
            }
@@ -1349,7 +1388,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("delete_policy", None));
                }
                Ok(())
            }
@@ -1372,7 +1411,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_policy", None));
                }
                Ok(())
            }
@@ -1397,7 +1436,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_policy_mapping", None));
                }
                Ok(())
            }
@@ -1420,7 +1459,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("delete_user", None));
                }
                Ok(())
            }
@@ -1443,7 +1482,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("delete_service_account", None));
                }
                Ok(())
            }
@@ -1467,7 +1506,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_user", None));
                }
                Ok(())
            }
@@ -1490,7 +1529,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_service_account", None));
                }
                Ok(())
            }
@@ -1513,7 +1552,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_group", None));
                }
                Ok(())
            }
@@ -1534,7 +1573,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("reload_site_replication_config", None));
                }
                Ok(())
            }
@@ -1577,7 +1616,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("signal_service", None));
                }
                validate_signal_service_protocol(sig, sub_sys, response.protocol_version)?;
                Ok(response)
@@ -1647,7 +1686,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("reload_pool_meta", None));
                }

                Ok(())
@@ -1671,7 +1710,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("stop_rebalance", None));
                }

                Ok(())
@@ -1705,7 +1744,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("load_rebalance_meta", None));
                }

                Ok(())
@@ -1733,7 +1772,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("start_decommission", None));
                }

                Ok(())
@@ -1757,7 +1796,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("decommission_cancel", None));
                }

                Ok(())
@@ -1781,7 +1820,7 @@ impl PeerRestClient {
                    if let Some(msg) = response.error_info {
                        return Err(Error::other(msg));
                    }
-                    return Err(Error::other(""));
+                    return Err(peer_failure_without_details("clear_decommission", None));
                }

                Ok(())
@@ -1927,6 +1966,8 @@ fn tier_config_reload_status_outcome(status: tonic::Status) -> TierConfigReloadO
 mod tests {
    use super::*;
    use crate::config::com::STORAGE_CLASS_SUB_SYS;
+    use crate::disk::error::DiskError;
+    use crate::disk::error_reduce::reduce_errs;
    use crate::layout::{disks_layout::DisksLayout, endpoints::SetupType};
    use rustfs_config::{ENV_KUBERNETES_SERVICE_HOST, ENV_LOCAL_ENDPOINT_HOST, ENV_STARTUP_TOPOLOGY_WAIT_MODE};
    use serde_json::Value;
@@ -2738,6 +2779,24 @@ mod tests {
        assert!(decode_remote_version_state_capability("node-a:9000", &nil).is_err());
    }

+    #[test]
+    fn cross_pool_fence_capability_decoder_fails_closed() {
+        let epoch = Uuid::new_v4();
+        let result = rustfs_protos::encode_cross_pool_fence_capability(1, "node-a:9000", epoch.as_bytes())
+            .expect("small capability response should encode");
+        assert_eq!(
+            decode_cross_pool_fence_capability("node-a:9000", &result).expect("valid capability should decode"),
+            (1, epoch)
+        );
+        for malformed in [&[][..], &[0, 0, 0][..], &result[..result.len() - 1]] {
+            assert!(decode_cross_pool_fence_capability("node-a:9000", malformed).is_err());
+        }
+        assert!(decode_cross_pool_fence_capability("node-b:9000", &result).is_err());
+        let nil = rustfs_protos::encode_cross_pool_fence_capability(1, "node-a:9000", Uuid::nil().as_bytes())
+            .expect("small capability response should encode");
+        assert!(decode_cross_pool_fence_capability("node-a:9000", &nil).is_err());
+    }
+
    struct TierMutationResponseFixture<'a> {
        version: u32,
        phase: TierMutationRpcPhase,
@@ -3060,4 +3119,115 @@ mod tests {
                && span.get("request_id").and_then(Value::as_str) == Some("req-peer-rest")
        }));
    }
+
+    /// Every operation name passed to `peer_failure_without_details` in this file.
+    const PEER_FAILURE_OPS: &[&str] = &[
+        "local_storage_info",
+        "server_info",
+        "get_cpus",
+        "get_net_info",
+        "get_partitions",
+        "get_os_info",
+        "get_se_linux_info",
+        "get_sys_config",
+        "get_sys_errors",
+        "get_mem_info",
+        "get_metrics",
+        "get_live_events",
+        "get_proc_info",
+        "start_profiling",
+        "load_bucket_metadata",
+        "delete_bucket_metadata",
+        "delete_policy",
+        "load_policy",
+        "load_policy_mapping",
+        "delete_user",
+        "delete_service_account",
+        "load_user",
+        "load_service_account",
+        "load_group",
+        "reload_site_replication_config",
+        "signal_service",
+        "reload_pool_meta",
+        "stop_rebalance",
+        "load_rebalance_meta",
+        "start_decommission",
+        "decommission_cancel",
+        "clear_decommission",
+    ];
+
+    #[test]
+    fn peer_failure_without_details_names_operation_and_bucket() {
+        for op in PEER_FAILURE_OPS {
+            let message = peer_failure_without_details(op, None).to_string();
+            assert!(message.contains(op), "{op} message must name the operation: {message}");
+        }
+
+        for op in ["load_bucket_metadata", "delete_bucket_metadata"] {
+            let message = peer_failure_without_details(op, Some("ops-bucket")).to_string();
+            assert!(message.contains(op), "{op} message must name the operation: {message}");
+            assert!(message.contains("ops-bucket"), "{op} message must name the bucket: {message}");
+        }
+    }
+
+    #[test]
+    fn peer_failure_without_details_keeps_one_reduce_errs_bucket_per_operation() {
+        // reduce_errs groups Io errors by kind plus rendered message: peers failing the
+        // same operation must stay a single dominant error instead of one bucket per peer.
+        let per_peer_errs = (0..4)
+            .map(|_| Some(DiskError::from(peer_failure_without_details("load_bucket_metadata", Some("shared")))))
+            .collect::<Vec<_>>();
+        let (count, dominant) = reduce_errs(&per_peer_errs, &[]);
+        assert_eq!(count, 4, "one shared failure must not split into per-peer buckets");
+        assert_eq!(
+            dominant,
+            Some(DiskError::from(peer_failure_without_details("load_bucket_metadata", Some("shared"))))
+        );
+
+        assert_ne!(
+            peer_failure_without_details("load_bucket_metadata", Some("shared")).to_string(),
+            peer_failure_without_details("delete_bucket_metadata", Some("shared")).to_string()
+        );
+        assert_ne!(
+            peer_failure_without_details("load_bucket_metadata", Some("bucket-a")).to_string(),
+            peer_failure_without_details("load_bucket_metadata", Some("bucket-b")).to_string()
+        );
+    }
+
+    #[test]
+    fn peer_failure_without_details_never_reads_as_a_network_failure() {
+        // `finalize_result` marks the peer offline and evicts its connection whenever the
+        // message matches a network needle. A peer that answered `success = false` is alive,
+        // so no operation or bucket name may push this text over that classifier.
+        for op in PEER_FAILURE_OPS {
+            let err = peer_failure_without_details(op, None);
+            assert!(
+                !PeerRestClient::is_network_like_error(&err),
+                "{op} must not read as a transport failure: {err}"
+            );
+
+            let scoped = peer_failure_without_details(op, Some("bucket-name"));
+            assert!(
+                !PeerRestClient::is_network_like_error(&scoped),
+                "{op} must not read as a transport failure: {scoped}"
+            );
+        }
+
+        // The bucket name is caller-supplied. Every needle carries a space, which S3 bucket
+        // names cannot, and the name is closed by `)` before the literal text resumes, so no
+        // needle can straddle the boundary either.
+        for bucket in [
+            "timed-out",
+            "connection-reset",
+            "transport-error",
+            "broken-pipe",
+            "unavailable-logs",
+        ] {
+            let err = peer_failure_without_details("load_bucket_metadata", Some(bucket));
+            assert!(
+                !PeerRestClient::is_network_like_error(&err),
+                "bucket {bucket} must not push the message over the network classifier: {err}"
+            );
+        }
+    }
 }
@@ -214,6 +214,21 @@ fn pool_write_quorum(participant_count: usize) -> usize {
    (participant_count / 2) + 1
 }

+/// Error for a peer that reported `success = false` without an error payload.
+///
+/// The message must stay identical across the peers of one operation: `reduce_errs`
+/// buckets `Error::Io` by kind plus rendered message, so any per-peer detail (address,
+/// timing) would split one shared failure into single-count buckets and downgrade a real
+/// dominant error into `ErasureWriteQuorum`.
+///
+/// `peer_rest_client` carries the same helper over `StorageError` for the same response shape.
+fn peer_failure_without_details(op: &str, bucket: Option<&str>) -> Error {
+    match bucket {
+        Some(bucket) => Error::other(format!("{op}({bucket}): peer returned failure without error details")),
+        None => Error::other(format!("{op}: peer returned failure without error details")),
+    }
+}
+
 fn reduce_pool_write_quorum_errs(per_pool_errs: &[Option<Error>]) -> Option<Error> {
    if per_pool_errs.is_empty() {
        return Some(Error::ErasureWriteQuorum);
@@ -854,7 +869,6 @@ impl PeerS3Client for LocalPeerS3Client {

 #[derive(Debug)]
 pub struct RemotePeerS3Client {
-    pub node: Option<Node>,
    pub pools: Option<Vec<usize>>,
    addr: String,
    /// Health tracker for connection monitoring
@@ -886,7 +900,6 @@ impl RemotePeerS3Client {
    pub fn new(node: Option<Node>, pools: Option<Vec<usize>>) -> Self {
        let addr = node.as_ref().map(|v| v.url.to_string()).unwrap_or_default();
        let client = Self {
-            node,
            pools,
            addr,
            health: Arc::new(DiskHealthTracker::new()),
@@ -905,10 +918,6 @@ impl RemotePeerS3Client {
            .map_err(|err| Error::other(format!("can not get client, err: {err}")))
    }

-    pub fn get_addr(&self) -> String {
-        self.addr.clone()
-    }
-
    /// Start health monitoring for the remote peer
    fn start_health_monitoring(&self) {
        let health = Arc::clone(&self.health);
@@ -1084,7 +1093,7 @@ impl PeerS3Client for RemotePeerS3Client {
                    return if let Some(err) = response.error {
                        Err(err.into())
                    } else {
-                        Err(Error::other(""))
+                        Err(peer_failure_without_details("heal_bucket", Some(bucket)))
                    };
                }

@@ -1111,7 +1120,7 @@ impl PeerS3Client for RemotePeerS3Client {
                    return if let Some(err) = response.error {
                        Err(err.into())
                    } else {
-                        Err(Error::other(""))
+                        Err(peer_failure_without_details("list_bucket", None))
                    };
                }
                let bucket_infos = response
@@ -1142,9 +1151,7 @@ impl PeerS3Client for RemotePeerS3Client {
                    return if let Some(err) = response.error {
                        Err(err.into())
                    } else {
-                        Err(Error::other(format!(
-                            "make_bucket({bucket}): peer returned failure without error details"
-                        )))
+                        Err(peer_failure_without_details("make_bucket", Some(bucket)))
                    };
                }

@@ -1168,7 +1175,7 @@ impl PeerS3Client for RemotePeerS3Client {
                    return if let Some(err) = response.error {
                        Err(err.into())
                    } else {
-                        Err(Error::other(""))
+                        Err(peer_failure_without_details("get_bucket_info", Some(bucket)))
                    };
                }
                let bucket_info = serde_json::from_str::<BucketInfo>(&response.bucket_info)?;
@@ -1196,7 +1203,7 @@ impl PeerS3Client for RemotePeerS3Client {
                    return if let Some(err) = response.error {
                        Err(err.into())
                    } else {
-                        Err(Error::other(""))
+                        Err(peer_failure_without_details("delete_bucket", Some(bucket)))
                    };
                }

@@ -1208,6 +1215,10 @@ impl PeerS3Client for RemotePeerS3Client {
    }
 }

+#[allow(
+    dead_code,
+    reason = "local bucket-heal path reached only by this file's tests (backlog#1823)"
+)]
 pub async fn heal_bucket_local(bucket: &str, opts: &HealOpts) -> Result<HealResultItem> {
    let disks = clone_drives().await;
    heal_bucket_local_on_disks(bucket, opts, disks).await
@@ -1404,6 +1415,10 @@ pub(crate) async fn heal_bucket_local_on_disks(
    }
 }

+#[allow(
+    dead_code,
+    reason = "reached only through heal_bucket_local, which only tests call (backlog#1823)"
+)]
 async fn clone_drives() -> Vec<Option<DiskStore>> {
    runtime_sources::local_disk_entries().await
 }
@@ -1585,15 +1600,7 @@ mod tests {
    }

    fn test_remote_peer(addr: &str) -> RemotePeerS3Client {
-        let node = Node {
-            url: url::Url::parse(addr).expect("test peer URL should parse"),
-            pools: vec![0],
-            is_local: false,
-            grid_host: addr.to_string(),
-        };
-
        RemotePeerS3Client {
-            node: Some(node),
            pools: Some(vec![0]),
            addr: addr.to_string(),
            health: Arc::new(DiskHealthTracker::new()),
@@ -2320,4 +2327,37 @@ mod tests {
            .collect::<Vec<_>>();
        assert_eq!(calls, vec![1, 1, 0, 0, 0, 0, 0, 0]);
    }
+
+    #[test]
+    fn peer_failure_without_details_names_operation_and_bucket() {
+        for op in ["heal_bucket", "make_bucket", "get_bucket_info", "delete_bucket"] {
+            let message = peer_failure_without_details(op, Some("ops-bucket")).to_string();
+            assert!(message.contains(op), "{op} message must name the operation: {message}");
+            assert!(message.contains("ops-bucket"), "{op} message must name the bucket: {message}");
+        }
+
+        let message = peer_failure_without_details("list_bucket", None).to_string();
+        assert!(message.contains("list_bucket"), "cluster-wide message must name the operation");
+        assert!(!message.trim().is_empty());
+    }
+
+    #[test]
+    fn peer_failure_without_details_keeps_one_reduce_errs_bucket_per_operation() {
+        // reduce_errs groups Io errors by kind plus rendered message: peers failing the
+        // same operation on the same bucket must still reach quorum as one dominant error.
+        let per_pool_errs = vec![
+            Some(peer_failure_without_details("delete_bucket", Some("shared"))),
+            Some(peer_failure_without_details("delete_bucket", Some("shared"))),
+            Some(peer_failure_without_details("delete_bucket", Some("shared"))),
+        ];
+        assert_eq!(
+            reduce_pool_write_quorum_errs(&per_pool_errs),
+            Some(peer_failure_without_details("delete_bucket", Some("shared")))
+        );
+
+        assert_ne!(
+            peer_failure_without_details("delete_bucket", Some("shared")),
+            peer_failure_without_details("get_bucket_info", Some("shared"))
+        );
+    }
 }
@@ -48,10 +48,6 @@ impl RemoteClient {
        Self { addr: endpoint }
    }

-    pub fn from_url(url: url::Url) -> Self {
-        Self { addr: url.to_string() }
-    }
-
    fn build_ping_request() -> PingRequest {
        let mut fbb = flatbuffers::FlatBufferBuilder::new();
        let payload = fbb.create_vector(b"health-check");
@@ -39,7 +39,6 @@ use rustfs_config::{
 };
 use std::sync::LazyLock;

-#[allow(dead_code)]
 #[allow(clippy::declare_interior_mutable_const)]
 /// Default KVS for audit webhook settings.
 pub static DEFAULT_AUDIT_WEBHOOK_KVS: LazyLock<KVS> = LazyLock::new(|| {
@@ -117,7 +116,6 @@ pub static DEFAULT_AUDIT_WEBHOOK_KVS: LazyLock<KVS> = LazyLock::new(|| {
    ])
 });

-#[allow(dead_code)]
 #[allow(clippy::declare_interior_mutable_const)]
 /// Default KVS for audit MQTT settings.
 pub static DEFAULT_AUDIT_MQTT_KVS: LazyLock<KVS> = LazyLock::new(|| {
@@ -375,7 +373,6 @@ pub static DEFAULT_AUDIT_NATS_KVS: LazyLock<KVS> = LazyLock::new(|| {
    ])
 });

-#[allow(dead_code)]
 pub static DEFAULT_AUDIT_PULSAR_KVS: LazyLock<KVS> = LazyLock::new(|| {
    KVS(vec![
        KV {
@@ -46,7 +46,6 @@ use rustfs_config::{
    SCANNER_SUB_SYS,
 };
 use rustfs_filemeta::FileInfo;
-use rustfs_utils::path::SLASH_SEPARATOR;
 use serde_json::{Map, Value};
 use std::collections::{HashMap, HashSet};
 use std::sync::LazyLock;
@@ -200,8 +199,6 @@ pub const STORAGE_CLASS_SUB_SYS: &str = "storage_class";

 pub const COMMA_SEPARATED_LISTS: &[&str] = &[rustfs_config::oidc::OIDC_SCOPES, rustfs_config::oidc::OIDC_OTHER_AUDIENCES];

-static CONFIG_BUCKET: LazyLock<String> = LazyLock::new(|| format!("{RUSTFS_META_BUCKET}{SLASH_SEPARATOR}{CONFIG_PREFIX}"));
-
 type ServerConfigDecryptFn = crate::bucket::migration::LegacyBlobDecryptFn;

 static SERVER_CONFIG_DECRYPT_FN: LazyLock<RwLock<Option<ServerConfigDecryptFn>>> = LazyLock::new(|| RwLock::new(None));
@@ -12,12 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.

-use crate::error::{Error, Result};
 use rustfs_config::server_config::{KV, KVS};
 use rustfs_config::{DEFAULT_HEAL_BITROT_CYCLE_SECS, HEAL_BITROT_CYCLE};
-use rustfs_utils::string::parse_bool;
 use std::sync::LazyLock;
-use std::time::Duration;

 pub static DEFAULT_KVS: LazyLock<KVS> = LazyLock::new(|| {
    KVS(vec![KV {
@@ -26,59 +23,3 @@ pub static DEFAULT_KVS: LazyLock<KVS> = LazyLock::new(|| {
        hidden_if_empty: false,
    }])
 });
-
-#[derive(Debug, Default)]
-pub struct Config {
-    pub bitrot: String,
-    pub sleep: Duration,
-    pub io_count: usize,
-    pub drive_workers: usize,
-    pub cache: Duration,
-}
-
-impl Config {
-    pub fn bitrot_scan_cycle(&self) -> Duration {
-        self.cache
-    }
-
-    pub fn get_workers(&self) -> usize {
-        self.drive_workers
-    }
-
-    pub fn update(&mut self, nopts: &Config) {
-        self.bitrot = nopts.bitrot.clone();
-        self.io_count = nopts.io_count;
-        self.sleep = nopts.sleep;
-        self.drive_workers = nopts.drive_workers;
-    }
-}
-
-const RUSTFS_BITROT_CYCLE_IN_MONTHS: u64 = 1;
-
-fn parse_bitrot_config(s: &str) -> Result<Duration> {
-    match parse_bool(s) {
-        Ok(enabled) => {
-            if enabled {
-                Ok(Duration::from_secs_f64(0.0))
-            } else {
-                Ok(Duration::from_secs_f64(-1.0))
-            }
-        }
-        Err(_) => {
-            if !s.ends_with("m") {
-                return Err(Error::other("unknown format"));
-            }
-
-            match s.trim_end_matches('m').parse::<u64>() {
-                Ok(months) => {
-                    if months < RUSTFS_BITROT_CYCLE_IN_MONTHS {
-                        return Err(Error::other(format!("minimum bitrot cycle is {RUSTFS_BITROT_CYCLE_IN_MONTHS} month(s)")));
-                    }
-
-                    Ok(Duration::from_secs(months * 30 * 24 * 60))
-                }
-                Err(err) => Err(Error::other(err)),
-            }
-        }
-    }
-}
@@ -13,11 +13,9 @@
 // limitations under the License.

 // #730: configuration migration keeps legacy subsystem definitions available behind this module.
-#![allow(dead_code)]

 mod audit;
 pub mod com;
-#[allow(dead_code)]
 pub mod heal;
 mod notify;
 mod oidc;
@@ -101,6 +101,7 @@ const DEFAULT_RRS_STORAGE_CLASS: &str = "EC:1";
 const ZERO_SET_DRIVE_COUNT_ERROR: &str = "set drive count must be greater than zero";

 pub static DEFAULT_INLINE_BLOCK: usize = 128 * 1024;
+const DEFAULT_INLINE_OBJECT_BUDGET: usize = 2 * DEFAULT_INLINE_BLOCK;

 pub static DEFAULT_KVS: LazyLock<KVS> = LazyLock::new(|| {
    let kvs = vec![
@@ -150,6 +151,8 @@ pub struct Config {
    optimize: Option<String>,
    inline_block: usize,
    initialized: bool,
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    inline_block_explicit: bool,
    #[serde(skip)]
    standard_parities: Vec<PoolParity>,
    #[serde(skip)]
@@ -186,6 +189,10 @@ impl Config {
    /// A topology-bound lookup fails closed for unknown drive counts and for
    /// deserialized legacy configurations that have no pool topology. Legacy
    /// callers retain scalar compatibility through [`Self::get_parity_for_sc`].
+    #[allow(
+        dead_code,
+        reason = "per-set parity resolution asserted by this file's tests (backlog#1823)"
+    )]
    pub(crate) fn parity_for_sc(&self, sc: &str, drives_per_set: usize) -> Option<usize> {
        if !self.initialized {
            return None;
@@ -233,17 +240,19 @@ impl Config {
            .map(|(pool_index, pool)| (pool_index, pool.drives_per_set))
    }

-    pub fn should_inline(&self, shard_size: i64, versioned: bool) -> bool {
-        if shard_size < 0 {
+    pub fn should_inline(&self, shard_size: i64, data_shards: usize, versioned: bool) -> bool {
+        if shard_size < 0 || data_shards == 0 {
            return false;
        }

        let shard_size = shard_size as usize;
-
-        let mut inline_block = DEFAULT_INLINE_BLOCK;
-        if self.initialized {
-            inline_block = self.inline_block;
-        }
+        // Keep the historical two-data-shard object budget while preventing
+        // wider EC layouts from multiplying the maximum inline object size.
+        let inline_block = if self.initialized && self.inline_block_explicit {
+            self.inline_block
+        } else {
+            (DEFAULT_INLINE_OBJECT_BUDGET / data_shards).min(DEFAULT_INLINE_BLOCK)
+        };

        if versioned {
            shard_size <= inline_block / 8
@@ -392,6 +401,7 @@ fn lookup_config_for_pools_with_env(
    }

    let optimize = overrides.optimize;
+    let inline_block_explicit = overrides.inline_block.is_some();
    let inline_block = if let Some(value) = overrides.inline_block {
        let block = value
            .parse::<bytesize::ByteSize>()
@@ -424,6 +434,7 @@ fn lookup_config_for_pools_with_env(
        optimize,
        inline_block,
        initialized: true,
+        inline_block_explicit,
        standard_parities,
        rrs_parities,
    })
@@ -541,22 +552,26 @@ mod tests {
    }

    #[test]
-    fn should_inline_preserves_exact_default_shard_boundaries() {
-        let config = Config::default();
+    fn should_inline_scales_default_threshold_by_data_shards() {
+        let config = lookup_config_for_pools_with_env(&KVS::new(), &[3, 12], no_env_overrides())
+            .expect("default inline policy should resolve for EC2+1 and EC8+4");

-        for (case, shard_size, versioned, expected) in [
-            ("unversioned below", 128 * 1024 - 1, false, true),
-            ("unversioned exact", 128 * 1024, false, true),
-            ("unversioned above", 128 * 1024 + 1, false, false),
-            ("versioned below", 16 * 1024 - 1, true, true),
-            ("versioned exact", 16 * 1024, true, true),
-            ("versioned above", 16 * 1024 + 1, true, false),
-            ("negative", -1, false, false),
+        for (case, shard_size, data_shards, versioned, expected) in [
+            ("EC2+1 unversioned exact", 128 * 1024, 2, false, true),
+            ("EC2+1 unversioned above", 128 * 1024 + 1, 2, false, false),
+            ("EC2+1 versioned exact", 16 * 1024, 2, true, true),
+            ("EC2+1 versioned above", 16 * 1024 + 1, 2, true, false),
+            ("EC8+4 unversioned exact", 32 * 1024, 8, false, true),
+            ("EC8+4 unversioned above", 32 * 1024 + 1, 8, false, false),
+            ("EC8+4 versioned exact", 4 * 1024, 8, true, true),
+            ("EC8+4 versioned above", 4 * 1024 + 1, 8, true, false),
+            ("negative", -1, 2, false, false),
+            ("zero data shards", 0, 0, false, false),
        ] {
            assert_eq!(
-                config.should_inline(shard_size, versioned),
+                config.should_inline(shard_size, data_shards, versioned),
                expected,
-                "{case}: shard_size={shard_size}, versioned={versioned}"
+                "{case}: shard_size={shard_size}, data_shards={data_shards}, versioned={versioned}"
            );
        }
    }
@@ -577,13 +592,28 @@ mod tests {
            let shard_size = erasure.shard_file_size(object_size);
            assert_eq!(shard_size, expected_shard_size, "{case}: object_size={object_size}");
            assert_eq!(
-                config.should_inline(shard_size, versioned),
+                config.should_inline(shard_size, erasure.data_shards, versioned),
                expected,
                "{case}: object_size={object_size}, shard_size={shard_size}, versioned={versioned}"
            );
        }
    }

+    #[test]
+    fn explicit_inline_block_preserves_fixed_per_shard_rollback() {
+        let overrides = StorageClassEnvOverrides {
+            inline_block: Some("128KiB".to_string()),
+            ..Default::default()
+        };
+        let config = lookup_config_for_pools_with_env(&KVS::new(), &[12], overrides)
+            .expect("explicit inline block should resolve for EC8+4");
+
+        assert!(config.should_inline(128 * 1024, 8, false));
+        assert!(!config.should_inline(128 * 1024 + 1, 8, false));
+        assert!(config.should_inline(16 * 1024, 8, true));
+        assert!(!config.should_inline(16 * 1024 + 1, 8, true));
+    }
+
    #[test]
    fn write_capability_contract_only_accepts_implemented_layouts() {
        assert_eq!(SUPPORTED_WRITE_CLASSES, [STANDARD, RRS]);
@@ -777,6 +807,7 @@ mod tests {
        let encoded = serde_json::to_string(&cfg).expect("config should serialize");
        assert!(!encoded.contains("standard_parities"));
        assert!(!encoded.contains("rrs_parities"));
+        assert!(!encoded.contains("inline_block_explicit"));

        let decoded: Config = serde_json::from_str(&encoded).expect("legacy scalar config should deserialize");
        assert_eq!(decoded.get_parity_for_sc(STANDARD), Some(2));
@@ -786,6 +817,25 @@ mod tests {
        assert!(validate_parity(0, 0).is_err());
    }

+    #[test]
+    fn explicit_inline_block_survives_config_round_trip() {
+        let cfg = lookup_config_for_pools_with_env(
+            &KVS::new(),
+            &[12],
+            StorageClassEnvOverrides {
+                inline_block: Some("128KiB".to_string()),
+                ..Default::default()
+            },
+        )
+        .expect("explicit inline block should resolve");
+        assert!(cfg.should_inline(100 * 1024, 8, false));
+
+        let encoded = serde_json::to_string(&cfg).expect("config should serialize");
+        assert!(encoded.contains("\"inline_block_explicit\":true"));
+        let decoded: Config = serde_json::from_str(&encoded).expect("explicit inline config should deserialize");
+        assert!(decoded.should_inline(100 * 1024, 8, false));
+    }
+
    #[test]
    fn lookup_config_reads_rrs_from_class_rrs_key() {
        // Regression: kvs.get(RRS) used RRS="REDUCED_REDUNDANCY" instead of
--- a/Show More
+++ b/Show More