diff --git a/docs/release-control/v6/internal/subsystems/agent-lifecycle.md b/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
index a074ff067..90804f06e 100644
--- a/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
+++ b/docs/release-control/v6/internal/subsystems/agent-lifecycle.md
@@ -1658,7 +1658,11 @@ the intentionally sparse public response.
    baseline for Linux md arrays. `mdadm --detail` may enrich level, state,
    member, UUID, and rebuild fields when available, but missing or failing
    mdadm detail probes must not hide a kernel-reported md array from the
-   unified agent report.
+   unified agent report. Vendor fixed-width role maps must not be treated as
+   missing members: a QNAP system RAID1 array that reports `[24/2]` while both
+   active members occupy roles 24 and 25 has two configured members, not 22
+   failed disks; ordinary in-range degraded maps such as `[4/3] [UUU_]` retain
+   their missing-member semantics (#1688).
    Server-side lifecycle admission must preserve that same continuity across
    Pulse restart and upgrade. When a standalone host comes back with the same
    durable machine/report identity and token continuity, the shared admission
diff --git a/internal/hostagent/agent_metrics_test.go b/internal/hostagent/agent_metrics_test.go
index 3f7fee5bc..a8df934e6 100644
--- a/internal/hostagent/agent_metrics_test.go
+++ b/internal/hostagent/agent_metrics_test.go
@@ -251,6 +251,30 @@ func TestBuildReport(t *testing.T) {
 		mc.raidArraysFn = nil
 	})
 
+	t.Run("RAID collection preserves QNAP sparse role map health", func(t *testing.T) {
+		mc.raidArraysFn = func(ctx context.Context) ([]agentshost.RAIDArray, error) {
+			return parseMDStatArrays(`md13 : active raid1 sdb4[25] sda4[24]
+      458880 blocks super 1.0 [24/2] [UU______________________]
+      bitmap: 1/1 pages [4KB], 65536KB chunk`), nil
+		}
+
+		report, err := agent.buildReport(context.Background())
+		if err != nil {
+			t.Fatalf("buildReport failed: %v", err)
+		}
+		if len(report.RAID) != 1 {
+			t.Fatalf("expected 1 RAID array, got %d", len(report.RAID))
+		}
+		array := report.RAID[0]
+		if array.Device != "/dev/md13" || array.State != "active" {
+			t.Fatalf("unexpected QNAP RAID array summary: %+v", array)
+		}
+		if array.TotalDevices != 2 || array.ActiveDevices != 2 || array.WorkingDevices != 2 || array.FailedDevices != 0 {
+			t.Fatalf("unexpected QNAP RAID array counts: %+v", array)
+		}
+		mc.raidArraysFn = nil
+	})
+
 	// Test case 4: Ceph collection
 	t.Run("Ceph collection", func(t *testing.T) {
 		mc.cephStatusFn = func(ctx context.Context) (*CephClusterStatus, error) {
diff --git a/internal/hostagent/mdadm.go b/internal/hostagent/mdadm.go
index 3bc5c07e8..67a399384 100644
--- a/internal/hostagent/mdadm.go
+++ b/internal/hostagent/mdadm.go
@@ -214,9 +214,6 @@ func parseMDStatArraySection(deviceName string, section []string) agentshost.RAI
 			active, _ := strconv.Atoi(matches[2])
 			array.TotalDevices = total
 			array.ActiveDevices = active
-			if total > active && !strings.Contains(array.State, "degraded") {
-				array.State = appendMDStatState(array.State, "degraded")
-			}
 		}
 
 		if array.Operation == "" {
@@ -255,6 +252,15 @@ func parseMDStatArraySection(deviceName string, section []string) agentshost.RAI
 	if array.TotalDevices == 0 {
 		array.TotalDevices = array.ActiveDevices
 	}
+	if mdStatUsesSparseRoleBitmap(array, failedDevices) {
+		// QNAP's system RAID1 arrays expose a fixed-width bay/role bitmap such
+		// as [24/2] [UU______________________], while their active members use
+		// roles 24 and 25. Those unused bitmap positions are not failed disks.
+		array.TotalDevices = array.ActiveDevices
+	}
+	if array.TotalDevices > array.ActiveDevices && !strings.Contains(array.State, "degraded") {
+		array.State = appendMDStatState(array.State, "degraded")
+	}
 	if failedDevices == 0 && array.TotalDevices > array.ActiveDevices {
 		failedDevices = array.TotalDevices - array.ActiveDevices
 	}
@@ -265,6 +271,30 @@ func parseMDStatArraySection(deviceName string, section []string) agentshost.RAI
 	return array
 }
 
+func mdStatUsesSparseRoleBitmap(array agentshost.RAIDArray, failedDevices int) bool {
+	if !strings.EqualFold(array.State, "active") ||
+		!strings.EqualFold(array.Level, "raid1") ||
+		failedDevices != 0 ||
+		array.TotalDevices <= array.ActiveDevices ||
+		array.ActiveDevices == 0 {
+		return false
+	}
+
+	activeMembers := 0
+	for _, device := range array.Devices {
+		state := strings.ToLower(device.State)
+		if strings.Contains(state, "faulty") || strings.Contains(state, "spare") {
+			continue
+		}
+		activeMembers++
+		if device.Slot < array.TotalDevices {
+			return false
+		}
+	}
+
+	return activeMembers == array.ActiveDevices
+}
+
 func parseMDStatDeviceToken(token string, arrayState string) (agentshost.RAIDDevice, bool) {
 	token = strings.Trim(token, ",")
 	matches := mdTokenRe.FindStringSubmatch(token)
diff --git a/internal/hostagent/mdadm_test.go b/internal/hostagent/mdadm_test.go
index a3506224c..7652f2c2b 100644
--- a/internal/hostagent/mdadm_test.go
+++ b/internal/hostagent/mdadm_test.go
@@ -699,6 +699,38 @@ unused devices: <none>`
 	}
 }
 
+func TestParseMDStatArraysQNAPSystemRAIDRoleBitmap(t *testing.T) {
+	mdstat := `Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
+md1 : active raid1 sdb3[3] sda3[2]
+      3897062912 blocks super 1.0 [2/2] [UU]
+
+md321 : active raid1 sda5[2] sdb5[0]
+      6702656 blocks super 1.0 [2/2] [UU]
+      bitmap: 0/1 pages [0KB], 65536KB chunk
+
+md13 : active raid1 sdb4[25] sda4[24]
+      458880 blocks super 1.0 [24/2] [UU______________________]
+      bitmap: 1/1 pages [4KB], 65536KB chunk
+
+md9 : active raid1 sdb1[25] sda1[24]
+      530048 blocks super 1.0 [24/2] [UU______________________]
+      bitmap: 1/1 pages [4KB], 65536KB chunk`
+
+	arrays := parseMDStatArrays(mdstat)
+	if len(arrays) != 4 {
+		t.Fatalf("array count = %d, want 4", len(arrays))
+	}
+	for _, index := range []int{2, 3} {
+		array := arrays[index]
+		if array.State != "active" {
+			t.Fatalf("%s state = %q, want active", array.Device, array.State)
+		}
+		if array.TotalDevices != 2 || array.ActiveDevices != 2 || array.WorkingDevices != 2 || array.FailedDevices != 0 {
+			t.Fatalf("unexpected %s device counts: %+v", array.Device, array)
+		}
+	}
+}
+
 func TestListArrayDevicesError(t *testing.T) {
 	withReadProcMDStat(t, func() ([]byte, error) {
 		return nil, errors.New("read failed")