From 3340a755c16009197c3faf06f19c7fef6875a94b Mon Sep 17 00:00:00 2001
From: overtrue <anzhengchao@gmail.com>
Date: Sun, 6 Sep 2026 16:38:10 +0800
Subject: [PATCH] test(e2e): verify two-pool bootstrap metadata repair

---
 .../distributed_startup_regression_test.rs    | 589 ++++++++++++++++++
 1 file changed, 589 insertions(+)

diff --git a/crates/e2e_test/src/distributed_startup_regression_test.rs b/crates/e2e_test/src/distributed_startup_regression_test.rs
index ebe98d5a2..46ae63954 100644
--- a/crates/e2e_test/src/distributed_startup_regression_test.rs
+++ b/crates/e2e_test/src/distributed_startup_regression_test.rs
@@ -745,4 +745,593 @@ mod tests {
             sleep(Duration::from_millis(25)).await;
         }
     }
+
+    /// A stopped, initialized pool loses only its pool.bin object replicas.
+    /// Restart must repair both pools through their actual conditional writes.
+    #[tokio::test]
+    async fn test_two_pool_restart_repairs_missing_pool_metadata_via_bootstrap_cas() -> TestResult {
+        use crate::common::ClusterTopology;
+        use futures::FutureExt;
+        use std::path::PathBuf;
+
+        init_logging();
+        let run = uuid::Uuid::new_v4().to_string();
+        let artifact = std::env::var_os("RUSTFS_E2E_STARTUP_CAS_ARTIFACT_DIR")
+            .map(PathBuf::from)
+            .unwrap_or_else(std::env::temp_dir)
+            .join(format!("repair-startup-cas-{run}"));
+        std::fs::create_dir_all(&artifact)?;
+        let binary_dir = tempfile::tempdir()?;
+        let binary = prepare_startup_cas_binary(binary_dir.path(), &artifact)?;
+        probe_startup_cas_binary(&binary, &run, &artifact).await?;
+        let mut owned = RepairStartupCluster(Some(
+            RustFSTestClusterEnvironment::with_topology(ClusterTopology::per_node_pools(2, vec![vec![0], vec![1]])).await?,
+        ));
+        let cluster = owned.0.as_mut().expect("fixture owns its cluster");
+        assert_eq!(cluster.nodes.len(), 2);
+        for (pool, node) in cluster.nodes.iter().enumerate() {
+            assert_eq!(node.pool_idx, pool);
+            assert_eq!(node.data_dirs.len(), 2);
+        }
+        let volumes = cluster.rustfs_volumes_arg();
+        assert_eq!(volumes.split_whitespace().count(), 2);
+        cluster.set_env("RUSTFS_OBS_LOG_DIRECTORY", "");
+        cluster.set_env("RUSTFS_OBS_LOG_STDOUT_ENABLED", "true");
+        cluster.set_env("RUST_LOG", "rustfs=info,rustfs_ecstore=trace");
+        for key in [
+            "HTTP_PROXY",
+            "HTTPS_PROXY",
+            "ALL_PROXY",
+            "http_proxy",
+            "https_proxy",
+            "all_proxy",
+        ] {
+            cluster.set_env(key, "");
+        }
+        for key in ["NO_PROXY", "no_proxy"] {
+            cluster.set_env(key, "127.0.0.1,localhost");
+        }
+        let attempt = tokio::time::timeout(
+            Duration::from_secs(600),
+            std::panic::AssertUnwindSafe(async {
+                let mut first = RepairStartupPhase::new(cluster, &artifact, "initial")?;
+                let previous = run_repair_startup_phase(cluster, &binary, &mut first, None).await?;
+                let bucket = format!("repair-cas-{run}");
+                let key = "preserved/body";
+                let body = vec![0x6bu8; 256 * 1024];
+                tokio::time::timeout(Duration::from_secs(20), async {
+                    cluster.create_test_bucket(&bucket).await?;
+                    cluster.create_all_clients()?[0]
+                        .put_object()
+                        .bucket(&bucket)
+                        .key(key)
+                        .body(ByteStream::from(body.clone()))
+                        .send()
+                        .await?;
+                    repair_full_get(cluster, &bucket, key, &body).await
+                })
+                .await
+                .map_err(std::io::Error::other)??;
+
+                // Retain each Child until wait confirms exit; only then mutate
+                // the stopped fixture's exact pool1 object subtrees.
+                let stopped = stop_repair_cluster(cluster)?;
+                assert_eq!(stopped.len(), 2, "both initial children must be reaped before disk mutation");
+                std::fs::write(artifact.join("initial-stopped.json"), serde_json::to_vec_pretty(&stopped)?)?;
+                let mut before = Vec::new();
+                for (pool, node) in cluster.nodes.iter().enumerate() {
+                    for disk in &node.data_dirs {
+                        let root = std::fs::canonicalize(disk)?;
+                        assert!(root.starts_with(std::fs::canonicalize(&cluster.temp_dir)?));
+                        let snapshot = repair_disk_snapshot(&root)?;
+                        assert!(snapshot.contains_key(std::path::Path::new(".rustfs.sys/format.json")));
+                        assert!(snapshot.contains_key(std::path::Path::new(".rustfs.sys/pool.bin.identity/xl.meta")));
+                        assert!(snapshot.contains_key(std::path::Path::new(".rustfs.sys/pool.bin/xl.meta")));
+                        before.push((pool, root, snapshot));
+                    }
+                }
+                std::fs::write(artifact.join("before-removal.json"), serde_json::to_vec_pretty(&before)?)?;
+                for (pool, root, _) in &before {
+                    if *pool == 1 {
+                        let object = root.join(".rustfs.sys/pool.bin");
+                        assert_eq!(std::fs::canonicalize(&object)?, object, "no aliased deletion target");
+                        std::fs::remove_dir_all(&object)?;
+                        assert!(!object.try_exists()?);
+                    }
+                }
+                for (pool, root, snapshot) in &before {
+                    let mut expected = snapshot.clone();
+                    if *pool == 1 {
+                        expected.retain(|path, _| !path.starts_with(".rustfs.sys/pool.bin"));
+                    }
+                    assert_eq!(repair_disk_snapshot(root)?, expected, "only pool1's complete pool.bin objects may change");
+                }
+                assert_eq!(cluster.rustfs_volumes_arg(), volumes, "repair reuses identical topology, ports and roots");
+                let mut restart = RepairStartupPhase::new(cluster, &artifact, "repair")?;
+                assert_ne!(restart.nonce, first.nonce);
+                let repaired = run_repair_startup_phase(cluster, &binary, &mut restart, Some(&previous)).await?;
+                tokio::time::timeout(Duration::from_secs(20), repair_full_get(cluster, &bucket, key, &body))
+                    .await
+                    .map_err(std::io::Error::other)??;
+                std::fs::write(
+                    artifact.join("repair-proof.json"),
+                    serde_json::to_vec_pretty(&serde_json::json!({
+                        "initial": previous, "repair": repaired, "volumes": volumes,
+                        "negative_control": "NOT_RUN", "body_length": body.len(), "full_get_nodes": [0, 1],
+                    }))?,
+                )?;
+                Ok::<(), Box<dyn Error + Send + Sync>>(())
+            })
+            .catch_unwind(),
+        )
+        .await;
+        // Borrowed startup futures and their release guards have dropped here.
+        // Attempt every child even when an earlier wait or assertion failed.
+        let stopped = stop_repair_cluster(cluster);
+        eprintln!("two-pool repair CAS evidence: {}", artifact.display());
+        match attempt {
+            Ok(Ok(result)) => {
+                result?;
+                std::fs::write(artifact.join("repair-stopped.json"), serde_json::to_vec_pretty(&stopped?)?)?;
+                Ok(())
+            }
+            Ok(Err(panic)) => std::panic::resume_unwind(panic),
+            Err(error) => Err(std::io::Error::other(format!("two-pool repair fixture deadline: {error}")).into()),
+        }
+    }
+
+    // Unlike the general harness stop_node, keep a failed Child wait attached
+    // so Drop can retry without deleting a possibly active disk directory.
+    struct RepairStartupCluster(Option<RustFSTestClusterEnvironment>);
+
+    impl Drop for RepairStartupCluster {
+        fn drop(&mut self) {
+            if let Some(mut cluster) = self.0.take() {
+                if let Err(error) = stop_repair_cluster(&mut cluster) {
+                    eprintln!("repair child cleanup failed; preserving {}: {error}", cluster.temp_dir);
+                }
+                if cluster.nodes.iter().any(|node| node.process.is_some()) {
+                    std::mem::forget(cluster);
+                }
+            }
+        }
+    }
+
+    fn stop_repair_cluster(cluster: &mut RustFSTestClusterEnvironment) -> std::io::Result<Vec<serde_json::Value>> {
+        let mut stopped = Vec::new();
+        let mut failure = None;
+        for (node, state) in cluster.nodes.iter_mut().enumerate() {
+            let Some(child) = state.process.as_mut() else { continue };
+            let pid = child.id();
+            let deadline = std::time::Instant::now() + Duration::from_secs(5);
+            let waited = (|| {
+                if child.try_wait()?.is_none() {
+                    // Exit can race kill; the actual wait below decides whether
+                    // the child is gone, rather than a successful signal alone.
+                    let _ = child.kill();
+                }
+                loop {
+                    if child.try_wait()?.is_some() {
+                        return child.wait();
+                    }
+                    if std::time::Instant::now() >= deadline {
+                        return Err(std::io::Error::other(format!("node {node} pid {pid} did not exit")));
+                    }
+                    std::thread::sleep(Duration::from_millis(10));
+                }
+            })();
+            match waited {
+                Ok(status) => {
+                    stopped.push(serde_json::json!({"node": node, "pid": pid, "status": status.to_string()}));
+                    state.process = None;
+                }
+                Err(error) => {
+                    failure.get_or_insert(error);
+                }
+            }
+        }
+        failure.map_or(Ok(stopped), Err)
+    }
+
+    fn repair_disk_snapshot(
+        root: &std::path::Path,
+    ) -> std::io::Result<std::collections::BTreeMap<std::path::PathBuf, (u64, String)>> {
+        let mut snapshot = std::collections::BTreeMap::new();
+        let mut pending = vec![std::path::PathBuf::new()];
+        while let Some(relative) = pending.pop() {
+            if relative.components().count() > 64 || snapshot.len() > 10_000 {
+                return Err(std::io::Error::other("repair fixture snapshot exceeds its bound"));
+            }
+            for entry in std::fs::read_dir(root.join(&relative))? {
+                let entry = entry?;
+                let path = relative.join(entry.file_name());
+                let metadata = std::fs::symlink_metadata(entry.path())?;
+                if metadata.is_dir() {
+                    snapshot.insert(path.clone(), (0, "directory".to_owned()));
+                    pending.push(path);
+                } else if metadata.is_file() {
+                    snapshot.insert(path, (metadata.len(), startup_cas_sha256(&entry.path())?));
+                } else {
+                    return Err(std::io::Error::other("repair fixture contains a symlink or special file"));
+                }
+            }
+        }
+        Ok(snapshot)
+    }
+
+    async fn repair_full_get(cluster: &RustFSTestClusterEnvironment, bucket: &str, key: &str, body: &[u8]) -> TestResult {
+        for (node, client) in cluster.create_all_clients()?.iter().enumerate() {
+            let received = client
+                .get_object()
+                .bucket(bucket)
+                .key(key)
+                .send()
+                .await?
+                .body
+                .collect()
+                .await?
+                .into_bytes();
+            assert_eq!(received.as_ref(), body, "node {node} must return every preserved object byte");
+        }
+        Ok(())
+    }
+
+    struct RepairStartupPhase {
+        nonce: String,
+        artifact: std::path::PathBuf,
+        logs: Vec<std::path::PathBuf>,
+        disks: Vec<Vec<std::path::PathBuf>>,
+        endpoints: Vec<Vec<String>>,
+        releases: StartupCasReleases,
+    }
+
+    impl RepairStartupPhase {
+        fn new(
+            cluster: &mut RustFSTestClusterEnvironment,
+            artifact: &std::path::Path,
+            phase: &str,
+        ) -> Result<Self, Box<dyn Error + Send + Sync>> {
+            let artifact = artifact.join(phase);
+            std::fs::create_dir(&artifact)?;
+            let nonce = uuid::Uuid::new_v4().to_string();
+            cluster.set_env("RUSTFS_E2E_STARTUP_CAS_NONCE", &nonce);
+            let mut result = Self {
+                nonce,
+                artifact,
+                logs: Vec::new(),
+                disks: Vec::new(),
+                endpoints: Vec::new(),
+                releases: StartupCasReleases(Vec::new()),
+            };
+            for node in 0..2 {
+                let log = result.artifact.join(format!("node-{node}.log"));
+                let release = result.artifact.join(format!("release-{node}"));
+                assert!(!release.try_exists()?, "each startup has a new unreleased gate");
+                cluster.set_node_capture_log_path(node, log.to_string_lossy())?;
+                cluster.set_node_env(node, "RUSTFS_E2E_STARTUP_CAS_RELEASE", release.to_string_lossy())?;
+                result
+                    .disks
+                    .push(cluster.nodes[node].data_dirs.iter().map(std::path::PathBuf::from).collect());
+                result.endpoints.push(
+                    cluster.nodes[node]
+                        .data_dirs
+                        .iter()
+                        .map(|disk| format!("http://{}{disk}", cluster.nodes[node].address))
+                        .collect(),
+                );
+                result.logs.push(log);
+                result.releases.0.push(release);
+            }
+            Ok(result)
+        }
+    }
+
+    async fn run_repair_startup_phase(
+        cluster: &mut RustFSTestClusterEnvironment,
+        binary: &std::path::Path,
+        phase: &mut RepairStartupPhase,
+        previous: Option<&serde_json::Value>,
+    ) -> Result<serde_json::Value, Box<dyn Error + Send + Sync>> {
+        let mut startup = Box::pin(cluster.start_with_binary(binary));
+        let mut observer = Box::pin(wait_two_pool_startup_cas(phase, previous));
+        let (observed, finished) = tokio::select! {
+            observed = tokio::time::timeout(Duration::from_secs(120), &mut observer) => {
+                (observed.map_err(std::io::Error::other).and_then(|result| result), false)
+            }
+            result = &mut startup => {
+                (Err(std::io::Error::other(format!("startup ended before both unreleased repair gates: {result:?}"))), true)
+            }
+        };
+        drop(observer);
+        let released = phase.releases.release();
+        let drained = if finished {
+            Ok(())
+        } else {
+            tokio::time::timeout(Duration::from_secs(if observed.is_ok() { 60 } else { 5 }), &mut startup)
+                .await
+                .map_err(std::io::Error::other)
+                .map_err(|error| -> Box<dyn Error + Send + Sync> { error.into() })
+                .and_then(|result| result)
+        };
+        drop(startup);
+        let observed = observed?;
+        released?;
+        drained?;
+        for (node, process) in cluster.nodes.iter().enumerate() {
+            assert_eq!(observed["pids"][node], process.process.as_ref().expect("live phase child").id());
+        }
+        Ok(observed)
+    }
+
+    async fn wait_two_pool_startup_cas(
+        phase: &RepairStartupPhase,
+        previous: Option<&serde_json::Value>,
+    ) -> std::io::Result<serde_json::Value> {
+        use serde_json::{Value, json};
+        loop {
+            let logs = phase
+                .logs
+                .iter()
+                .map(|path| startup_cas_log(path))
+                .collect::<std::io::Result<Vec<_>>>()?;
+            let events: Vec<Vec<&Value>> = logs
+                .iter()
+                .map(|log| log.iter().filter(|event| event["nonce"] == phase.nonce).collect())
+                .collect();
+            if events
+                .iter()
+                .flat_map(|events| events.iter())
+                .any(|event| event["kind"] == "cas" && event["ok"] == false)
+            {
+                return Err(std::io::Error::other("normal two-pool startup produced a failed CAS; inspect phase logs"));
+            }
+            if !events.iter().all(|events| {
+                events
+                    .iter()
+                    .any(|event| event["kind"] == "gate" && event["slot_installed"] == false)
+            }) {
+                sleep(Duration::from_millis(25)).await;
+                continue;
+            }
+            let mut pids = Vec::new();
+            for records in &events {
+                let ready: Vec<_> = records.iter().filter(|event| event["kind"] == "observer-ready").collect();
+                assert_eq!(ready.len(), 1, "one real process per phase log");
+                assert!(ready[0]["pid"].as_u64().is_some());
+                assert!(records.iter().all(|event| event["pid"] == ready[0]["pid"]));
+                pids.push(ready[0]["pid"].clone());
+            }
+            assert_ne!(pids[0], pids[1]);
+            let source = &events[0];
+            let classified: Vec<_> = source
+                .iter()
+                .copied()
+                .filter(|event| event["kind"] == "startup-classifier")
+                .collect();
+            assert_eq!(classified.len(), 1, "the normal startup must classify once, without retrying failures");
+            let classified = classified[0];
+            let attempt = &classified["attempt"];
+            uuid::Uuid::parse_str(attempt.as_str().expect("real init attempt UUID")).expect("valid init attempt UUID");
+            assert_eq!(classified["elected_writer"], true);
+            assert_eq!(classified["needs_repair"], true);
+            assert_eq!(classified["repair_write_safe"], true);
+            assert_eq!(classified["topology_update"], previous.is_none());
+            assert!(
+                events[1]
+                    .iter()
+                    .all(|event| event["kind"] != "cas" || event["object"] != "pool.bin"),
+                "only elected pool0 may persist pool.bin"
+            );
+            let initial: Vec<_> = source
+                .iter()
+                .copied()
+                .filter(|event| {
+                    event["kind"] == "replica-read" && event["startup_phase"] == "load" && event["attempt"] == *attempt
+                })
+                .collect();
+            assert_eq!(initial.len(), 2, "complete initial reads of both real pools");
+            assert_eq!(initial[0]["batch"], initial[1]["batch"]);
+            let mut prepares = Vec::new();
+            let mut commits = Vec::new();
+            for pool in 0..2 {
+                let read: Vec<_> = initial.iter().filter(|event| event["pool"] == pool).collect();
+                assert_eq!(read.len(), 1);
+                let read = *read[0];
+                if let Some(previous) = previous.filter(|_| pool == 0) {
+                    assert_eq!(read["state"], "valid");
+                    assert_eq!(read["committed"], true);
+                    for field in [
+                        "payload_sha256",
+                        "raw_sha256",
+                        "version",
+                        "cluster_id",
+                        "epoch",
+                        "generation",
+                        "transaction_id",
+                        "etag",
+                    ] {
+                        assert_eq!(read[field], previous["replicas"][0][field], "pool0 baseline {field} is retained");
+                    }
+                } else {
+                    assert_eq!(read["state"], "missing");
+                    assert_eq!(read["cas"], "missing");
+                }
+                let mut pair = Vec::new();
+                for stage in ["prepare_cas", "commit_cas"] {
+                    let matching: Vec<_> = source
+                        .iter()
+                        .copied()
+                        .filter(|event| {
+                            event["kind"] == "cas"
+                                && event["object"] == "pool.bin"
+                                && event["phase"] == stage
+                                && event["pool"] == pool
+                                && event["attempt"] == *attempt
+                                && event["startup_phase"] == "persist"
+                        })
+                        .collect();
+                    assert_eq!(matching.len(), 1, "exactly one successful {stage} on actual pool {pool}");
+                    let cas = matching[0];
+                    assert_eq!(cas["ok"], true);
+                    assert_eq!(cas["tail_drained"], true);
+                    assert_eq!(cas["no_lock"], true);
+                    assert!(cas["etag"].as_str().is_some_and(|value| !value.is_empty()));
+                    assert!(cas["mod_time"].as_str().is_some_and(|value| !value.is_empty()));
+                    pair.push(cas);
+                }
+                if previous.is_some() && pool == 0 {
+                    assert_eq!(read["cas"], "existing");
+                    assert_eq!(pair[0]["if_match"], read["etag"]);
+                    assert!(pair[0]["if_none_match"].is_null());
+                } else {
+                    assert_eq!(pair[0]["if_none_match"], "*");
+                    assert!(pair[0]["if_match"].is_null());
+                }
+                assert_eq!(pair[1]["if_match"], pair[0]["etag"]);
+                assert!(pair[1]["if_none_match"].is_null());
+                assert_ne!(pair[0]["etag"], pair[1]["etag"]);
+                assert_ne!(pair[0]["payload_sha256"], pair[1]["payload_sha256"]);
+                prepares.push(pair[0]);
+                commits.push(pair[1]);
+            }
+            assert_eq!(
+                source
+                    .iter()
+                    .filter(|event| event["kind"] == "cas" && event["object"] == "pool.bin")
+                    .count(),
+                4
+            );
+            assert_eq!(prepares[0]["payload_sha256"], prepares[1]["payload_sha256"]);
+            assert_eq!(commits[0]["payload_sha256"], commits[1]["payload_sha256"]);
+            let mut replicas = Vec::new();
+            for pool in 0..2 {
+                let matching: Vec<_> = source
+                    .iter()
+                    .copied()
+                    .filter(|event| {
+                        event["kind"] == "replica-read"
+                            && event["startup_phase"] == "persist"
+                            && event["attempt"] == *attempt
+                            && event["pool"] == pool
+                            && event["payload_sha256"] == commits[pool]["payload_sha256"]
+                    })
+                    .collect();
+                assert_eq!(matching.len(), 1, "actual final complete decoded read for pool {pool}");
+                let replica = matching[0];
+                assert_eq!(replica["state"], "valid");
+                assert_eq!(replica["committed"], true);
+                assert_eq!(replica["pool_count"], 2);
+                assert_eq!(replica["raw_sha256"], replica["payload_sha256"]);
+                assert_eq!(replica["etag"], commits[pool]["etag"]);
+                assert_eq!(replica["cas"], "existing");
+                assert!(
+                    replica["cluster_id"]
+                        .as_str()
+                        .is_some_and(|value| uuid::Uuid::parse_str(value).is_ok())
+                );
+                assert!(
+                    replica["transaction_id"]
+                        .as_str()
+                        .is_some_and(|value| uuid::Uuid::parse_str(value).is_ok())
+                );
+                assert!(replica["epoch"].as_u64().is_some_and(|value| value > 0));
+                let expected_generation = match previous {
+                    Some(previous) => {
+                        previous["replicas"][0]["generation"]
+                            .as_u64()
+                            .expect("previous decoded generation")
+                            + 1
+                    }
+                    None => 1,
+                };
+                assert_eq!(replica["generation"], expected_generation);
+                if let Some(previous) = previous {
+                    assert_eq!(replica["cluster_id"], previous["replicas"][0]["cluster_id"]);
+                    assert_eq!(replica["epoch"], previous["replicas"][0]["epoch"]);
+                    assert_ne!(replica["transaction_id"], previous["replicas"][0]["transaction_id"]);
+                }
+                replicas.push(replica);
+            }
+            for field in [
+                "batch",
+                "version",
+                "cluster_id",
+                "epoch",
+                "generation",
+                "transaction_id",
+                "payload_sha256",
+            ] {
+                assert_eq!(replicas[0][field], replicas[1][field], "same decoded final revision: {field}");
+            }
+            let confirmed: Vec<_> = source
+                .iter()
+                .filter(|event| {
+                    event["kind"] == "confirmed"
+                        && event["attempt"] == *attempt
+                        && event["payload_sha256"] == replicas[0]["payload_sha256"]
+                        && event["generation"] == replicas[0]["generation"]
+                        && event["transaction_id"] == replicas[0]["transaction_id"]
+                })
+                .collect();
+            assert_eq!(confirmed.len(), 1);
+            let mut receivers = Vec::new();
+            for drive in 0..2 {
+                for cas in [prepares[1], commits[1]] {
+                    let matching: Vec<_> = events[1]
+                        .iter()
+                        .copied()
+                        .filter(|event| {
+                            event["kind"] == "receiver"
+                                && event["disk"] == phase.endpoints[1][drive]
+                                && event["dst_volume"] == ".rustfs.sys"
+                                && event["dst_path"] == "pool.bin"
+                                && event["etag"] == cas["etag"]
+                        })
+                        .collect();
+                    assert!(matching.len() <= 1, "one actual receiver per disk/CAS");
+                    if let Some(receiver) = matching.first() {
+                        assert_eq!(receiver["ok"], true);
+                        assert_eq!(receiver["target"], "bootstrap");
+                        assert_eq!(receiver["mod_time"], cas["mod_time"]);
+                        assert!(receiver["body_sha256"].as_str().is_some_and(|hash| hash.len() == 64));
+                        if startup_cas_remote_matches(&logs[0], receiver) == 1 {
+                            receivers.push(*receiver);
+                        }
+                    }
+                }
+            }
+            if receivers.len() != 4 {
+                // Remote started tracing may flush after direct receiver JSON.
+                sleep(Duration::from_millis(25)).await;
+                continue;
+            }
+            for (pool, disks) in phase.disks.iter().enumerate() {
+                for (drive, disk) in disks.iter().enumerate() {
+                    let raw = std::fs::read(disk.join(".rustfs.sys/pool.bin/xl.meta"))?;
+                    let latest = rustfs_filemeta::get_file_info(
+                        &raw,
+                        ".rustfs.sys",
+                        "pool.bin",
+                        "",
+                        rustfs_filemeta::FileInfoOpts {
+                            data: false,
+                            include_free_versions: false,
+                            include_part_checksums: false,
+                        },
+                    )
+                    .map_err(std::io::Error::other)?;
+                    assert!(!raw.is_empty());
+                    assert_eq!(latest.metadata.get("etag").map(String::as_str), commits[pool]["etag"].as_str());
+                    assert_eq!(
+                        latest.mod_time.map(|time| time.unix_timestamp_nanos().to_string()).as_deref(),
+                        commits[pool]["mod_time"].as_str()
+                    );
+                    std::fs::write(phase.artifact.join(format!("pool-{pool}-drive-{drive}-latest-xl.meta")), raw)?;
+                }
+            }
+            let proof = json!({"nonce": phase.nonce, "pids": pids, "classifier": classified, "initial": initial, "prepare": prepares, "commit": commits, "replicas": replicas, "receivers": receivers, "confirmed": confirmed});
+            std::fs::write(phase.artifact.join("cas-proof.json"), serde_json::to_vec_pretty(&proof)?)?;
+            return Ok(proof);
+        }
+    }
 }