diff --git a/docs/release-control/v6/internal/subsystems/agent-lifecycle.md b/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
index edbc7f7ea..8dd94d00a 100644
--- a/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
+++ b/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
@@ -15,6 +15,8 @@
 
 ## Purpose
 
+Unraid collection preserves optional nonnegative `mdNumDisks` as `numDisks` through the host report. Explicit zero survives JSON encoding; absent, negative, or malformed source counts remain unknown. This telemetry does not change enrollment or command authority; older agents retain unknown-count behaviour.
+
 ### Portable installer lifecycle ownership
 
 The shared shell installer lifecycle directory (outside the least-privilege
diff --git a/docs/release-control/v6/internal/subsystems/monitoring.md b/docs/release-control/v6/internal/subsystems/monitoring.md
index d39d98483..5e641c9fd 100644
--- a/docs/release-control/v6/internal/subsystems/monitoring.md
+++ b/docs/release-control/v6/internal/subsystems/monitoring.md
@@ -17,6 +17,8 @@
 
 ## Purpose
 
+Unraid host ingestion and canonical read-state reconstruction preserve the optional array disk count, distinguishing explicit zero from unknown. Storage assessment suppresses only the no-parity warning for an explicit zero-disk array; unknown counts retain the prior warning and disabled, invalid, or missing member evidence remains effective.
+
 Direct PBS backup polling correlates manifestless snapshots with current
 writer tasks before publishing guest backup-running state. The client queries
 running `backup` and `syncjob` task families separately with bounded pagination;
diff --git a/docs/release-control/v6/internal/subsystems/storage-recovery.md b/docs/release-control/v6/internal/subsystems/storage-recovery.md
index 3ca096331..32508454e 100644
--- a/docs/release-control/v6/internal/subsystems/storage-recovery.md
+++ b/docs/release-control/v6/internal/subsystems/storage-recovery.md
@@ -21,6 +21,8 @@
 
 ## Purpose
 
+Unraid `StorageMeta.numDisks` is optional source evidence: zero denotes an explicitly empty parity array, not proof that pools are protected or that a recovery point exists. Suppressing the no-parity warning for zero must not erase disk-failure evidence or grant storage/recovery authority.
+
 A manifestless PBS snapshot never becomes a successful recovery point and
 never advances backup age. Recovery mapping reports it as running while a live
 writer accounts for it or current-task visibility is unavailable; after a
diff --git a/docs/release-control/v6/internal/subsystems/unified-resources.md b/docs/release-control/v6/internal/subsystems/unified-resources.md
index af0f71be9..dbe212996 100644
--- a/docs/release-control/v6/internal/subsystems/unified-resources.md
+++ b/docs/release-control/v6/internal/subsystems/unified-resources.md
@@ -15,6 +15,8 @@
 
 ## Purpose
 
+Unraid adapters preserve optional `numDisks` in both host and storage metadata, including explicit zero in JSON and absence for unknown counts. Disk count is topology evidence only: changing it must not change canonical host/storage identity. The storage projection uses the monitoring-owned assessment so an explicit pool-only array does not acquire a no-parity warning.
+
 Own canonical resource identity, type normalization, typed views, and
 cross-source deduplication.
 Storage metadata may expose source-authored alias IDs as compatibility evidence
diff --git a/internal/hostagent/unraid.go b/internal/hostagent/unraid.go
index 20c77ef3f..ed46a0a4e 100644
--- a/internal/hostagent/unraid.go
+++ b/internal/hostagent/unraid.go
@@ -185,6 +185,11 @@ func parseUnraidStatusOutput(output string) (*agentshost.UnraidStorage, error) {
 		NumMissing:   parseUnraidIntField(fields, "mdNumMissing"),
 	}
 
+	// Zero is meaningful for pool-only systems; missing or invalid is unknown.
+	if count, err := strconv.Atoi(strings.TrimSpace(fields["mdNumDisks"])); err == nil && count >= 0 {
+		storage.NumDisks = &count
+	}
+
 	indexes := collectUnraidIndexes(fields)
 	disks := make([]agentshost.UnraidDisk, 0, len(indexes))
 	for _, idx := range indexes {
diff --git a/internal/hostagent/unraid_test.go b/internal/hostagent/unraid_test.go
index a5fb58621..33a92b3f9 100644
--- a/internal/hostagent/unraid_test.go
+++ b/internal/hostagent/unraid_test.go
@@ -2,6 +2,7 @@ package hostagent
 
 import (
 	"context"
+	"encoding/json"
 	"os"
 	"path/filepath"
 	"testing"
@@ -384,3 +385,54 @@ func TestCollectUnraidStorageUsesResolvedMdcmd(t *testing.T) {
 		t.Fatalf("CollectUnraidStorage() = %#v, want populated storage", storage)
 	}
 }
+
+func TestParseUnraidStatusArrayDiskCount(t *testing.T) {
+	for _, tc := range []struct {
+		name, field string
+		want        *int
+	}{
+		{"pool-only", "mdNumDisks=0", newIntForArrayCount(0)},
+		{"array", "mdNumDisks=3", newIntForArrayCount(3)},
+		{"missing", "", nil},
+		{"invalid", "mdNumDisks=unknown", nil},
+		{"negative", "mdNumDisks=-1", nil},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			storage, err := parseUnraidStatusOutput("mdState=STARTED\n" + tc.field + "\n")
+			if err != nil {
+				t.Fatal(err)
+			}
+			if tc.want == nil {
+				if storage.NumDisks != nil {
+					t.Fatalf("unexpected count %d", *storage.NumDisks)
+				}
+			} else if storage.NumDisks == nil || *storage.NumDisks != *tc.want {
+				t.Fatalf("count = %v, want %d", storage.NumDisks, *tc.want)
+			}
+			if !storage.ArrayStarted {
+				t.Fatal("disk count must not change service state")
+			}
+			wire, err := json.Marshal(storage)
+			if err != nil {
+				t.Fatal(err)
+			}
+			var fields map[string]json.RawMessage
+			if err := json.Unmarshal(wire, &fields); err != nil {
+				t.Fatal(err)
+			}
+			count, present := fields["numDisks"]
+			if present != (tc.want != nil) {
+				t.Fatalf("count presence in %s", wire)
+			}
+			if tc.want != nil {
+				var got int
+				if err := json.Unmarshal(count, &got); err != nil || got != *tc.want {
+					t.Fatalf("wire count = %s", count)
+				}
+			}
+
+		})
+	}
+}
+
+func newIntForArrayCount(n int) *int { return &n }
diff --git a/internal/models/models.go b/internal/models/models.go
index 83dd00a44..318c8631a 100644
--- a/internal/models/models.go
+++ b/internal/models/models.go
@@ -739,6 +739,7 @@ type HostUnraidStorage struct {
 	SyncAction   string           `json:"syncAction,omitempty"`
 	SyncProgress float64          `json:"syncProgress,omitempty"`
 	SyncErrors   int64            `json:"syncErrors,omitempty"`
+	NumDisks     *int             `json:"numDisks,omitempty"` // nil means the agent did not report an array disk count.
 	NumProtected int              `json:"numProtected,omitempty"`
 	NumDisabled  int              `json:"numDisabled,omitempty"`
 	NumInvalid   int              `json:"numInvalid,omitempty"`
diff --git a/internal/monitoring/monitor.go b/internal/monitoring/monitor.go
index e5f1268f7..aa795b652 100644
--- a/internal/monitoring/monitor.go
+++ b/internal/monitoring/monitor.go
@@ -3896,6 +3896,7 @@ func hostUnraidFromReadStateView(unraid *unifiedresources.HostUnraidMeta) *model
 		SyncAction:   unraid.SyncAction,
 		SyncProgress: unraid.SyncProgress,
 		SyncErrors:   unraid.SyncErrors,
+		NumDisks:     unraid.NumDisks,
 		NumProtected: unraid.NumProtected,
 		NumDisabled:  unraid.NumDisabled,
 		NumInvalid:   unraid.NumInvalid,
diff --git a/internal/monitoring/monitor_agents.go b/internal/monitoring/monitor_agents.go
index 56a5cf1da..a4bf3c3af 100644
--- a/internal/monitoring/monitor_agents.go
+++ b/internal/monitoring/monitor_agents.go
@@ -3415,6 +3415,7 @@ func (m *Monitor) ApplyHostReport(report agentshost.Report, tokenRecord *config.
 			SyncAction:   syncAction,
 			SyncProgress: syncProgress,
 			SyncErrors:   report.Unraid.SyncErrors,
+			NumDisks:     report.Unraid.NumDisks,
 			NumProtected: numProtected,
 			NumDisabled:  numDisabled,
 			NumInvalid:   numInvalid,
diff --git a/internal/monitoring/monitor_host_agents_test.go b/internal/monitoring/monitor_host_agents_test.go
index 95c0d8c3b..ef5976097 100644
--- a/internal/monitoring/monitor_host_agents_test.go
+++ b/internal/monitoring/monitor_host_agents_test.go
@@ -5654,3 +5654,34 @@ func TestMonitorConstructionWiresNotificationDeliveryReconciliation(t *testing.T
 		}
 	}
 }
+
+func TestApplyHostReportPreservesPoolOnlyUnraidCount(t *testing.T) {
+	monitor := &Monitor{
+		state: models.NewState(), alertManager: alerts.NewManager(),
+		hostTokenBindings: make(map[string]string), config: &config.Config{},
+		rateTracker: NewRateTracker(),
+	}
+	t.Cleanup(func() { monitor.alertManager.Stop() })
+	var report agentshost.Report
+	// Exercise the agent wire format: explicit zero must survive omitempty.
+	err := json.Unmarshal([]byte(`{"agent":{"id":"pool-only","version":"test"},"host":{"id":"pool-only","hostname":"pool-only"},"unraid":{"arrayStarted":true,"numDisks":0}}`), &report)
+	if err != nil {
+		t.Fatal(err)
+	}
+	report.Timestamp = time.Now().UTC()
+	host, err := monitor.ApplyHostReport(report, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if host.Unraid == nil || host.Unraid.NumDisks == nil || *host.Unraid.NumDisks != 0 {
+		t.Fatalf("lost explicit zero: %+v", host.Unraid)
+	}
+	record := unifiedresources.HostIngestRecord(host)
+	restored := hostUnraidFromReadStateView(record.Resource.Agent.Unraid)
+	if restored == nil || restored.NumDisks == nil || *restored.NumDisks != 0 {
+		t.Fatalf("canonical round trip lost explicit zero: %+v", restored)
+	}
+	if assessment := storagehealth.AssessUnraidStorage(*restored); assessment.Level != storagehealth.RiskHealthy {
+		t.Fatalf("pool-only host raised storage risk: %+v", assessment)
+	}
+}
diff --git a/internal/storagehealth/topology.go b/internal/storagehealth/topology.go
index 25b61af35..d18f5a0b8 100644
--- a/internal/storagehealth/topology.go
+++ b/internal/storagehealth/topology.go
@@ -299,7 +299,9 @@ func AssessUnraidStorage(storage models.HostUnraidStorage) Assessment {
 		}
 	}
 
-	if storage.ArrayStarted && !parityConfigured {
+	// Unraid can start pool services with no array. Only an explicit zero
+	// suppresses this warning, preserving behaviour for older agents.
+	if storage.ArrayStarted && !parityConfigured && (storage.NumDisks == nil || *storage.NumDisks != 0) {
 		addReason("unraid_no_parity", RiskWarning, "Unraid array is running without parity protection")
 	}
 	if storage.ArrayStarted && parityConfigured && !parityHealthy {
diff --git a/internal/storagehealth/topology_test.go b/internal/storagehealth/topology_test.go
index e61c095a1..01ea69283 100644
--- a/internal/storagehealth/topology_test.go
+++ b/internal/storagehealth/topology_test.go
@@ -382,3 +382,38 @@ func TestAssessPBSDatastoreHighUsage(t *testing.T) {
 		t.Fatalf("unexpected reasons %+v", assessment.Reasons)
 	}
 }
+
+func TestAssessUnraidStoragePoolOnlyParity(t *testing.T) {
+	zero, three := 0, 3
+	for _, tc := range []struct {
+		name        string
+		count       *int
+		wantWarning bool
+	}{
+		{"explicit pool-only", &zero, false},
+		{"array without parity", &three, true},
+		{"legacy unknown count", nil, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			assessment := AssessUnraidStorage(models.HostUnraidStorage{
+				ArrayStarted: true, NumDisks: tc.count,
+				Disks: []models.HostUnraidDisk{{Name: "cache", Role: "cache", Status: "online"}},
+			})
+			found := false
+			for _, reason := range assessment.Reasons {
+				if reason.Code == "unraid_no_parity" {
+					found = true
+				}
+			}
+			if found != tc.wantWarning {
+				t.Fatalf("no-parity warning = %v; reasons %+v", found, assessment.Reasons)
+			}
+		})
+	}
+	assessment := AssessUnraidStorage(models.HostUnraidStorage{
+		ArrayStarted: true, NumDisks: &zero, NumDisabled: 1,
+	})
+	if assessment.Level != RiskCritical {
+		t.Fatalf("zero count masked disk failure: %+v", assessment)
+	}
+}
diff --git a/internal/unifiedresources/adapters.go b/internal/unifiedresources/adapters.go
index 64e429670..935baf82f 100644
--- a/internal/unifiedresources/adapters.go
+++ b/internal/unifiedresources/adapters.go
@@ -416,6 +416,7 @@ func resourceFromHost(host models.Host) (Resource, ResourceIdentity) {
 			SyncAction:        host.Unraid.SyncAction,
 			SyncProgress:      host.Unraid.SyncProgress,
 			SyncErrors:        host.Unraid.SyncErrors,
+			NumDisks:          host.Unraid.NumDisks,
 			NumProtected:      host.Unraid.NumProtected,
 			NumDisabled:       host.Unraid.NumDisabled,
 			NumInvalid:        host.Unraid.NumInvalid,
@@ -726,6 +727,7 @@ func resourceFromHostUnraidStorage(host models.Host) (Resource, ResourceIdentity
 			ArrayState:   host.Unraid.ArrayState,
 			SyncAction:   host.Unraid.SyncAction,
 			SyncProgress: host.Unraid.SyncProgress,
+			NumDisks:     host.Unraid.NumDisks,
 			NumProtected: host.Unraid.NumProtected,
 			NumDisabled:  host.Unraid.NumDisabled,
 			NumInvalid:   host.Unraid.NumInvalid,
diff --git a/internal/unifiedresources/adapters_test.go b/internal/unifiedresources/adapters_test.go
index 09795546f..4768e5a8a 100644
--- a/internal/unifiedresources/adapters_test.go
+++ b/internal/unifiedresources/adapters_test.go
@@ -1969,3 +1969,14 @@ func TestResourceFromGuestSetsProxmoxGuestKey(t *testing.T) {
 		t.Fatalf("keyless VM must not carry a guest key, got %q", keyless.ProxmoxGuestKey)
 	}
 }
+
+func TestUnraidArrayDiskCountAdapters(t *testing.T) {
+	for _, count := range []*int{nil, new(int), func() *int { n := 3; return &n }()} {
+		host := models.Host{ID: "pool-only", Hostname: "pool-only", Unraid: &models.HostUnraidStorage{NumDisks: count}}
+		resource, _ := resourceFromHost(host)
+		storage, _ := resourceFromHostUnraidStorage(host)
+		if !reflect.DeepEqual(resource.Agent.Unraid.NumDisks, count) || !reflect.DeepEqual(storage.Storage.NumDisks, count) {
+			t.Fatalf("adapters lost disk count %v", count)
+		}
+	}
+}
diff --git a/internal/unifiedresources/canonical_ids_types_test.go b/internal/unifiedresources/canonical_ids_types_test.go
index 5537d33b3..08c477179 100644
--- a/internal/unifiedresources/canonical_ids_types_test.go
+++ b/internal/unifiedresources/canonical_ids_types_test.go
@@ -554,3 +554,37 @@ func TestWearoutUnreportedSentinelIsNegativeOne(t *testing.T) {
 		t.Fatal("the unreported sentinel must not fall inside the real 0-100 reporting range")
 	}
 }
+
+func TestUnraidDiskCountJSONAndIdentity(t *testing.T) {
+	host := models.Host{ID: "pool-only", Hostname: "pool-only", Unraid: &models.HostUnraidStorage{}}
+	_, unknownIdentity := resourceFromHostUnraidStorage(host)
+	zero := 0
+	host.Unraid.NumDisks = &zero
+	resource, zeroIdentity := resourceFromHostUnraidStorage(host)
+	if unknownIdentity.MachineID != zeroIdentity.MachineID {
+		t.Fatal("disk count changed storage identity")
+	}
+	data, err := json.Marshal(resource.Storage)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(data), `"numDisks":0`) {
+		t.Fatalf("explicit zero lost: %s", data)
+	}
+	var restored StorageMeta
+	if err := json.Unmarshal(data, &restored); err != nil {
+		t.Fatal(err)
+	}
+	if restored.NumDisks == nil || *restored.NumDisks != 0 {
+		t.Fatal("zero lost in round trip")
+	}
+	host.Unraid.NumDisks = nil
+	resource, _ = resourceFromHostUnraidStorage(host)
+	data, err = json.Marshal(resource.Storage)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(string(data), `"numDisks"`) {
+		t.Fatalf("unknown count became known: %s", data)
+	}
+}
diff --git a/internal/unifiedresources/types.go b/internal/unifiedresources/types.go
index 826c508e5..0eef1d26c 100644
--- a/internal/unifiedresources/types.go
+++ b/internal/unifiedresources/types.go
@@ -454,6 +454,7 @@ type StorageMeta struct {
 	ArrayState   string  `json:"arrayState,omitempty"`
 	SyncAction   string  `json:"syncAction,omitempty"`
 	SyncProgress float64 `json:"syncProgress,omitempty"`
+	NumDisks     *int    `json:"numDisks,omitempty"` // nil means the agent did not report an array disk count.
 	NumProtected int     `json:"numProtected,omitempty"`
 	NumDisabled  int     `json:"numDisabled,omitempty"`
 	NumInvalid   int     `json:"numInvalid,omitempty"`
@@ -748,6 +749,7 @@ type HostUnraidMeta struct {
 	SyncAction        string               `json:"syncAction,omitempty"`
 	SyncProgress      float64              `json:"syncProgress,omitempty"`
 	SyncErrors        int64                `json:"syncErrors,omitempty"`
+	NumDisks          *int                 `json:"numDisks,omitempty"` // nil means the agent did not report an array disk count.
 	NumProtected      int                  `json:"numProtected,omitempty"`
 	NumDisabled       int                  `json:"numDisabled,omitempty"`
 	NumInvalid        int                  `json:"numInvalid,omitempty"`
diff --git a/pkg/agents/host/report.go b/pkg/agents/host/report.go
index ae34b0aea..d484c4733 100644
--- a/pkg/agents/host/report.go
+++ b/pkg/agents/host/report.go
@@ -491,6 +491,7 @@ type UnraidStorage struct {
 	SyncAction   string       `json:"syncAction,omitempty"`
 	SyncProgress float64      `json:"syncProgress,omitempty"`
 	SyncErrors   int64        `json:"syncErrors,omitempty"`
+	NumDisks     *int         `json:"numDisks,omitempty"` // nil means the agent did not report an array disk count.
 	NumProtected int          `json:"numProtected,omitempty"`
 	NumDisabled  int          `json:"numDisabled,omitempty"`
 	NumInvalid   int          `json:"numInvalid,omitempty"`