Raid Array Data Recovery

We deliver engineering-grade recovery for software & hardware RAIDs, NAS, SAN/DAS, and rack servers—2-disk mirrors through 32-disk arrays. Clients include home users, SMEs, enterprises, and public sector. Free diagnostics and clear options before work begins.

Send-in: Label each drive’s slot/position, place in anti-static bags, cushion well in a padded envelope or small box, include contact details, and post or drop off. We always work from write-blocked clones, never originals.

Top NAS brands in the UK (representative popular models)

1. Synology – DiskStation DS224+, DS423+, DS723+, DS923+, DS1522+; RackStation RS1221+, RS3621xs+

2. QNAP – TS-464, TS-473A, TS-873A, TVS-h674, TS-431K; rack TS-x53DU, TS-x73AU

3. Western Digital (WD) – My Cloud EX2 Ultra, EX4100, PR4100, DL2100

4. Seagate/LaCie – LaCie 2big/6big/12big, Seagate IronWolf NAS enclosures

5. Buffalo – TeraStation 3420/5420/6420, LinkStation 220/520

6. NETGEAR – ReadyNAS RN424, RN524X, RN628X

7. TerraMaster – F2-423, F4-423, F5-422, U-series rack

8. ASUSTOR – AS5304T, AS6604T, LOCKERSTOR 4/8

9. Drobo (legacy) – 5N2, B810n

10. Thecus – N5810PRO, N7710-G

11. iXsystems – TrueNAS Mini X/XL, R-series (FreeNAS/TrueNAS based)

12. LenovoEMC (legacy) – ix2, ix4, px4

13. Zyxel – NAS542, NAS326

14. D-Link – DNS-320L, DNS-340L

15. Promise – VTrak/Vess NAS

16. Ugreen – consumer NAS ranges (newer)

17. OWC – Jellyfish (Pro NAS)

18. QSAN – XN3002T/XN5004T

19. Infortrend – EonNAS

20. HPE StoreEasy – 1460/1660/1860 (Windows NAS)

(Models representative; we recover all families and capacities.)

Top RAID server / rack platforms (representative)

1. Dell EMC PowerEdge – R540/R640/R650/R750, T440/T640

2. HPE ProLiant – DL360/DL380 Gen10/Gen11, ML350, DL325

3. Lenovo ThinkSystem – SR630/SR650, ST550

4. Supermicro SuperServer – 1029/2029/AS-series

5. Fujitsu PRIMERGY – RX2540, TX2550

6. Cisco UCS C-Series – C220/C240

7. NetApp FAS/AFF – FAS27xx/A2xx (LUN exports)

8. Dell EMC PowerVault – ME4012/ME4024/ME4084 (DAS/SAN)

9. Infortrend EonStor – GS/GX/Gene

10. Promise VTrak – E-class, J-class JBODs

11. Areca – ARC-1883/1886 series controllers

12. Adaptec by Microchip – ASR-71605/71685/8405/8805

13. QNAP Enterprise – TS-h1277XU/TS-x83XU

14. Synology RackStation – RS4021xs+, RS1221+

15. IBM/Lenovo (legacy) – x3650, M-series with ServeRAID

Professional RAID recovery workflow (what we actually do)

1. Forensic intake & label verification – record serials, order, enclosure/controller, filesystem/LUN layout.

2. Clone every member first – hardware imagers (PC-3000, DDI, Atola) with unstable-media profiles (head-select, zone priority, reverse passes, adaptive timeouts).

3. Controller/metadata capture – export foreign configs (LSI/Adaptec/Areca), mdadm/LVM superblocks, ZFS labels, Synology DSM/QNAP md/LVM layers.

4. Virtual array reconstruction – discover stripe size, parity rotation, disk order, start offsets, 512e/4Kn sector size, any write-hole patterns; build a virtual RAID from the clones.

5. Filesystem/LUN repair on the virtual image – NTFS/ReFS, APFS/HFS+, EXT/XFS/ZFS/Btrfs; journal replay, B-tree & bitmap repair, orphan grafting; no writes to members.

6. RAID with encryption – BitLocker/FileVault/LUKS/SED: decrypt using valid keys on the virtual image; otherwise salvage plaintext remnants.

7. Verification & delivery – SHA-256 manifests, sample-open testing (DB/video/mail), secure handover.

Top 75 RAID errors we recover (and how)

Core assembly & configuration

1. Unknown disk order → parity analysis on stripes to infer order; verify with signature checks.

2. Unknown stripe size → entropy/CRC tests over 16–1024 KB candidates; confirm against file headers.

3. Wrong start offset → detect filesystem superblock/GPT alignment; adjust member offsets.

4. Mixed sector sizes (512e/4Kn) → normalise during virtual build; remap logical block addressing.

5. Foreign configuration conflicts → dump all controller metadata; select last consistent epoch; ignore stale sets.

6. Stale/partial rebuild metadata → roll back to pre-rebuild epoch; exclude degraded writes.

7. Accidental array re-initialisation → ignore new headers; reconstruct from deep scan of old parity/metadata; mount virtually.

8. Accidental disk reorder during maintenance → parity-validation to restore order; test montage on small windows before full.

9. Parity rotation schema unknown → profile (RAID-5 left-asymmetric/right-symmetric; RAID-6 P+Q rows) via parity math.

10. Inconsistent stripe unit per member → detect by misaligned headers; rebuild with corrected unit size.

Member/media failures

11. Single-disk failure in RAID-5 → clone all members; compute missing stripe via parity; export.

12. Dual-disk failure in RAID-6 → clone; solve P/Q equations; recover stripes; export.

13. Multiple member read instabilities → per-head cloning on weak HDDs; error map merges; fill holes from parity.

14. Unreadable sectors on parity member → compute from data disks; mark map.

15. Head crash on one member → donor HSA swap; minimal SA work; clone readable ranges; rest from parity.

16. Translator corruption on HDD member → rebuild translator; clone; parity completes holes.

17. SSD wear-out in RAID-10 → ECC-tuned imaging; prefer surviving mirror; re-mirror virtually.

18. NVMe namespace drop → admin commands enumerate; clone namespace directly.

Controller/firmware faults

19. LSI/Avago firmware bug (cache write-back loss) → detect incomplete stripes; roll back with journal/FS log.

20. Cache battery failure (BBU) leading to write hole → locate inconsistent stripes; reconstruct via filesystem journal and parity consensus.

21. Adaptec “degraded good” member → force offline copy in virtual set; ignore controller’s stale mark.

22. Areca metadata mismatch → extract binary headers; pick consistent generation; rebuild virtually.

23. Intel RST fakeraid confusion → import metadata; rebuild as mdadm-compatible virtual RAID.

24. Promise/VTrak write journal loss → parity verify; use FS intent logs for correction.

Rebuild & migration issues

25. Rebuild halted with UREs → image failing member with tiny blocks; parity repair missing sectors.

26. Capacity-mismatched replacement → trim virtual member to common size; rebuild above min-size.

27. Expand/reshape interrupted → locate old/new metadata; roll back to last consistent map; export.

28. Stripe size changed mid-life → segment array history; export from stable epoch(s).

29. Bad sector reallocation during rebuild → image before reallocation; remap in virtual RAID.

Filesystem & LUN corruption on RAID

30. NTFS $MFT damage on RAID-5 → reconstruct $MFT using $MFTMirr; replay $LogFile; recover.

31. ReFS metadata errors → use CoW snapshots to roll back; salvage from shadow copies.

32. EXT/XFS journal replays → mount readonly; xfs_repair with logzero if needed.

33. ZFS pool with missing vdev → import readonly, use zdb to map blocks; copy files (partial if needed).

34. Btrfs RAID1/10 in NAS → btrfs-restore from good copy of chunks; heal references.

35. APFS on RAID LUN → object map/spacemap rebuild on the LUN image; snapshot export.

36. HFS+ catalog/extent B-tree damage → rebuild trees; graft orphans.

NAS-specific stack problems

37. Synology DSM mdadm/LVM layers damaged → reconstruct md arrays; reassemble LVM; mount ext4/btrfs; export.

38. QNAP mdraid + LVM2 → same as above; handle legacy EXT3/4 + thin LVM.

39. XFS on mdraid (older NETGEAR) → xfs_repair on the LUN clone; export data.

40. Btrfs metadata duplication in Synology → use surviving mirror metadata to restore tree root; recover.

41. “System volume degraded” after DSM update → discard new config on virtual; mount previous epoch.

Partitioning / sector geometry

42. GPT headers overwritten → rebuild from secondary GPT + FS signatures.

43. Hybrid MBR/GPT mismatches → normalize to GPT; correct LUN boundaries.

44. 512e vs 4Kn sector mismatch after migration → translate during virtual assembly.

Encryption on top of RAID

45. BitLocker over RAID → require recovery key; decrypt LUN image; then rebuild FS.

46. LUKS/dm-crypt on mdadm → use header/backup header; PBKDF; decrypt; mount.

47. SED at array level → unlock via controller; if unavailable, keys required; otherwise carve plaintext residues.

Accidental/administrative errors

48. Deleted RAID set → deep scan members for previous metadata; reconstruct last coherent array.

49. Quick-initialized array → ignore new headers; recover from old stripe map.

50. Accidental “create single disk” on member → member still has old data; virtualize back into set.

51. Hot-spare promoted incorrectly → identify promotion point; restore correct order.

Performance/IO anomalies that cause loss

52. Link instability (SAS/SATA CRCs) → rehost to stable backplane; clone; rebuild virtually.

53. Expander misrouting → audit enclosure map; correct path; re-image.

54. Backplane power brownouts → bench PSU; image under stable rails.

Virtualisation & datastore on RAID

55. VMFS datastore header damage → rebuild VMFS structures; stitch VMDKs.

56. Hyper-V CSV corruption → repair NTFS/ReFS; consolidate AVHDX chain.

57. VHDX/VMDK snapshot chain broken → map parents; fix grain tables/BAT; mount child.

58. Thin-provision & zero-fill confusion → honour allocation maps; ignore unallocated noise.

59. RDM/iSCSI LUN loss → rebuild target mapping; mount extents.

Advanced parity anomalies

60. Write-hole stripes (RAID-5) → use FS logs to choose correct version per stripe.

61. Dual parity mismatch (RAID-6) → recompute Q with Galois field ops; validate via headers.

62. Rotating parity with missing last drive → infer rotation by majority vote across stripes.

Edge cases & legacy

63. Dynamic Disks (Windows) spanning → rebuild LDM metadata; re-join extents.

64. Apple SoftRAID/RAID-0/1 → parse Apple RAID headers; virtual assemble.

65. NetApp WAFL LUN inside RAID → recover LUN, then filesystem within.

66. Extents truncated at array end → export partials with integrity notes.

67. Controller foreign import overwrote headers → salvage from clone of members; rebuild manually.

68. Battery-backed cache lost data after power cut → preference to journal-consistent epoch.

69. Sector remap storms during rebuild → halt rebuild; image members; reconstruct virtually.

70. NAS expansion added different-size drives → logical min-size virtual array; export.

71. Volume group metadata missing (LVM) → scan PV headers; re-create VG; mount LVs readonly.

72. mdadm superblock version conflicts → pick consistent superblock set; ignore mismatched.

73. Btrfs scrub aborted mid-repair → mount degraded; use btrfs restore; copy.

74. ZFS resilver interrupted → import readonly; copy healthy files; note gaps.

75. Parity disk physically OK but logical stale → exclude stale member from parity math.

Top 20 problems with virtual RAID / storage stacks (and our approach)

1. VMFS header loss on RAID LUN → rebuild VMFS; re-index VMDKs.

2. Corrupt VMDK descriptor + intact flat → regenerate descriptor; mount.

3. Broken VHDX chain (Hyper-V) → reconstruct parent links; merge diffs.

4. ReFS CSV metadata damage → roll back via shadow copies; CoW map validate.

5. Thin-provision overcommit → export allocated blocks only; warn on sparse gaps.

6. iSCSI target table loss → recover targets from config backups; remount LUNs.

7. NFS export corruption (NAS) → bypass NFS; mount underlying volume on clone.

8. LVM thin pool metadata loss → rebuild from pool metadata recovery; export LVs.

9. Docker/Container volumes on RAID → recover overlay2 layers; rebuild volumes.

10. Ceph/Gluster bricks on mdadm → export object/chunk data; rehydrate.

11. KVM qcow2 mapping damage → fix L1/L2 tables; convert to raw.

12. Snapshots filled the datastore → delete broken snapshots on clone; consolidate.

13. SR-IOV/iSCSI offload bugs → rehost storage; image; repair on clone.

14. RDM pointer loss → rebuild mapping; mount physical LUN image.

15. Xen .vhd differencing chain issues → rebuild BAT/parent IDs; merge.

16. vSAN disk group fail (forensic export) → per-component extraction; limited salvage.

17. Proxmox ZFS pool degraded → import readonly; zdb map; copy.

18. TrueNAS/Bhyve images missing → search zvol snapshots; clone block devices.

19. VM encryption keys lost → require KMS/KEK; otherwise carve unencrypted caches only.

20. NDMP/backup appliance LUN loss → reconstruct catalog; restore to alternate target.

Why choose Sheffield Data Recovery

• 25+ years of RAID/NAS/Server recoveries across every major vendor and controller

• Clone-first, controller-aware process (parity math, rotation analysis, stripe inference)

• Advanced mechanical/firmware/FTL tooling for HDD, SSD, and NVMe members

• Forensic discipline: write-blocked imaging, SHA-256 verification, documented results

• Free diagnostics with evidence-based options before work begins

Ready to start? Package the disks safely (anti-static + padded envelope/small box, labelled by slot/order) and post or drop them in. Our RAID engineers will assess and present the fastest, safest path to your data.