Leicester Data Recovery – No.1 RAID 0/1/5/6/10 Data Recovery Specialists (25+ Years)

With over 25 years’ experience, Leicester Data Recovery recovers complex RAID and multi-disk systems for home users, SMEs, large enterprises and public sector teams across Leicester, Coventry, the Midlands and Wales. We handle controller faults, mis-rebuilds, multi-disk failures, parity issues, filesystem corruption, virtualisation stacks and encrypted volumes (with valid keys).

RAID & Platforms We Support

• Arrays: RAID 0 / 1 / 5 / 6 / 10 / 50 / 60, JBOD, SHR, mdadm/LVM, Windows Storage Spaces, ZFS/Btrfs pools.

• File systems: NTFS, ReFS, APFS/HFS+, ext3/ext4, XFS, Btrfs, ZFS, VMFS, NFS/SMB shares.

• Hardware/Software: HBA/RAID controllers (Adaptec/Microchip, LSI/Avago/Broadcom MegaRAID, Areca, Dell PERC, HPE Smart Array, IBM/Lenovo ServeRAID), NAS appliances, hypervisors (VMware/Hyper-V/Proxmox/Xen).

15 Major NAS Brands in the UK (with representative popular models)

1. Synology – DS923+, DS423+, RS3621xs+, DS220+.

2. QNAP – TS-453D, TS-673A, TVS-h874, TS-431K.

3. Western Digital (WD) – My Cloud EX2 Ultra, PR4100, My Cloud Home Duo.

4. Netgear ReadyNAS – RN424, RN524X, RR2304.

5. Buffalo – TeraStation TS3420DN/TS3420RN, LinkStation LS220D.

6. Seagate / LaCie – LaCie 2big/6big/12big, Seagate NAS Pro (legacy).

7. Asustor – AS5304T, Lockerstor 4/8 (AS6704T/AS6708T).

8. TerraMaster – F4-423, F2-423, T9-423.

9. Thecus – N5810PRO, N7710-G (legacy but common in recovery).

10. ioSafe (fire/water-resist, Synology-based) – 218/1522+ derivatives.

11. TrueNAS / iXsystems – TrueNAS Mini X, R-/X-series.

12. Drobo (legacy/discontinued, still widely used) – Drobo 5N/5N2, B810n.

13. LenovoEMC / Iomega (legacy) – ix2/ix4/px4-300d.

14. Zyxel – NAS326/NAS540.

15. D-Link – ShareCenter DNS-320L/DNS-340L.

(If your NAS isn’t listed, we still support it.)

15 Common Rack-Server Vendors (with representative RAID-oriented models)

1. Dell EMC – PowerEdge R740/R750/R760, R540, R640 (PERC).

2. HPE – ProLiant DL380 Gen10/Gen11, DL360, ML350 (Smart Array).

3. Lenovo – ThinkSystem SR650/SR630, SR645 (ServeRAID/Broadcom).

4. Supermicro – 1U/2U SuperServer 1029/2029/6029 families.

5. Fujitsu – PRIMERGY RX2540/RX2520.

6. Cisco – UCS C-Series C220/C240 M5–M7.

7. Huawei – FusionServer Pro 2288H.

8. Inspur – NF5280M6/M7.

9. Gigabyte Server – R272/R282 series.

10. ASUS Server – RS520/RS720, ESC series (RAID/HBA options).

11. Tyan – Thunder/Transport rack platforms.

12. QCT (Quanta) – D52BQ/D43K series.

13. IBM (legacy System x) – x3650/x3550 M4/M5 in the field.

14. Apple (legacy) – Mac Pro racks with external RAID (ATTO/Areca).

15. NetApp / Dell Compellent / HPE MSA – For block LUNs presented to hosts (we recover underlying RAID/LUNs when needed).

Typical RAID/NAS Fault Spectrum We Cover

Multiple disk failures, rebuild failures/aborts, wrong disk order, wrong stripe/offset guesses, controller NVRAM loss, firmware bugs, silent bit-rot, sector remapping storms, hot-swap mistakes, accidental initialisation, pool/pointer corruption, iSCSI LUN loss, thin-provision snapshot explosions and more.

Our Professional RAID Recovery Approach (Summary)

1. Evidence-safe intake & imaging – Per-disk hardware imaging (PC-3000/Atola/DeepSpar) with head-maps, timeouts, power cycles; never rebuild on originals.

2. Metadata acquisition – Pull controller/NAS metadata (superblocks, mdadm headers, DDF, ZFS labels, Btrfs chunks).

3. Virtual array reconstruction – Determine disk order, start offsets, block/stripe size, parity rotation, write-hole behaviour.

4. File system rebuild – Mount images read-only; repair NTFS/ReFS/APFS/ext4/XFS/Btrfs/ZFS; carve where needed.

5. Integrity & hand-off – Hash validation, spot-open critical files, staged hand-over.

50 RAID Errors We Recover From – With Technical Recovery Notes

Array Composition / Disk-Order / Geometry

1. Unknown disk order – Fix: parity analysis, entropy/marker matching, superblock offsets to infer order.

2. Unknown stripe size – Fix: heuristic trials on 16–1024 KB, verify FS continuity; parity consistency checks.

3. Unknown parity rotation (RAID-5) – Fix: left/right, synchronous/asynchronous trial with checksum validation.

4. Wrong start offset – Fix: locate FS signatures (NTFS $MFT, XFS superblock, APFS NXSB) to anchor true offsets.

5. Inter-disk write-hole – Fix: journal and log repair; parity reconcile around small windows.

Disk Failures / Media
6. Multiple concurrent disk failures – Fix: per-disk imaging; selective head reads; reconstruct virtual array from best images.
7. Silent sector remapping storms – Fix: track reallocations; image with skip/late-fill; parity reconstruct missing ranges.
8. Pending/UNC sector bursts – Fix: soft→hard passes; targeted re-reads; fill with parity/calculated blocks.
9. SMART trip causing premature drop – Fix: image outside controller; add virtually after imaging.
10. Head degradation on one member – Fix: head-map imaging; substitute virtual disk for that member.

Controller / Firmware / NVRAM
11. Controller NVRAM loss (geometry forgotten) – Fix: pull on-disk metadata; reconstruct manually.
12. Firmware bug corrupts metadata – Fix: copy metadata from healthy mirrors; hand-edit known fields (Areca/LSI).
13. Battery-backed cache (BBU) failure – Fix: flush policy recovery; rebuild FS journaling inconsistencies.
14. Foreign config mis-import – Fix: discard foreign; build virtual array from images to avoid destructive writes.
15. Controller swaps between models – Fix: ignore controller; assemble from raw images with correct parameters.

Human Errors
16. Accidental initialise/new array creation – Fix: recover prior metadata via superblock history; carve old FS.
17. Wrong disk hot-swap to wrong bay – Fix: reorder by serials and log evidence; parity validation.
18. Forced rebuild onto wrong drive – Fix: salvage donor content; revert using pre-rebuild images; re-calc parity window.
19. Clone written back to original – Fix: isolate; recover from remaining members + parity; carve overwritten ranges where possible.
20. Disk labelled incorrectly – Fix: identify by WWN/serial and SMART; map back to slot positions.

Rebuild / Degrade Behaviour
21. Rebuild aborts mid-way – Fix: image failing member; resume virtually from last good LBA.
22. Background patrol read causes second failure – Fix: halt array; image both; merge best-of reads by LBA.
23. Auto-rebuild to smaller disk – Fix: re-map geometry; virtual resize; correct capacity mismatch.
24. Hot-spare promoted with stale data – Fix: detect pre-promotion timestamp; exclude stale ranges; recompute.
25. Degraded RAID-6 loses a second disk – Fix: dual parity recovery; fill missing stripes from P/Q.

Parity / Consistency / Checksums
26. Parity mismatches across stripes – Fix: parity correction in virtual space; prefer majority data copies.
27. Stale stripes post power-loss – Fix: journal/log replay; checksum-guided selection per stripe.
28. Rotating parity map corrupted – Fix: infer rotation pattern from surviving metadata.
29. RAID-50/60 tier parity confusion – Fix: reconstruct child RAID-5/6 first; then parent RAID-0.
30. Write-back cache inconsistency – Fix: re-order using controller logs if present; otherwise FS repair with conservative assumptions.

Filesystem on Top of RAID
31. NTFS $MFT corruption – Fix: reconstruct from $MFTMirr, $LogFile; orphan recovery.
32. ReFS metadata damage – Fix: block-clone salvage; integrity streams; export intact objects.
33. XFS log corruption – Fix: xlog recovery; inode btree rebuild.
34. ext4 superblock/journal loss – Fix: alternate superblocks; journal replay; inode scan.
35. Btrfs chunk map loss – Fix: scan superblocks; rebuild chunk/extent trees; subvol snapshot recovery.
36. ZFS pool won’t import – Fix: read labels; choose txg; roll-back/forward to last consistent transaction.

NAS-Specific / LUNs
37. Synology SHR metadata loss – Fix: mdadm superblock rebuild; SHR mapping re-derivation.
38. QNAP mdadm arrays with cache SSD – Fix: assemble data + cache order; ensure dirty cache flush virtually.
39. iSCSI LUN corruption (thin-provisioned) – Fix: rebuild LUN headers/extent maps; mount VMFS/NTFS within.
40. Snapshot schedule explosion (Btrfs/ZFS) – Fix: mount earlier snapshot; export; later prune/repair.
41. Dedup/compression side-effects – Fix: respect block references; extract physical blocks coherently.

Capacity / Sector Geometry / 4Kn
42. Mixed 512e and 4Kn members – Fix: normalise sector size in images; re-stripe virtually.
43. HPA/DCO trimmed members – Fix: remove HPA/DCO in image; match reported sizes.
44. Grown defect list expansion during rebuild – Fix: pause; image with conservative passes; re-integrate best copy.

Encryption / Security (lawful, with keys)
45. Controller-level encryption (Opal/SED) – Fix: unlock with credentials; then image plaintext.
46. Volume encryption (BitLocker/LUKS) – Fix: decrypt from recovery key/passphrase after imaging; then FS work.
47. NAS-bridge encryption – Fix: repair/match bridge; present plaintext stream; recover LUN/share.

Edge Cases / Misc
48. Firmware-induced timeouts on certain drives – Fix: vendor-specific firmware quiesce; slow imaging.
49. Backplane / expander faults – Fix: by-pass to HBA; per-disk imaging; ignore faulty backplane.
50. Disaster (fire/water) – Fix: electronic stabilisation, conservative imaging, parity-assisted fills; prioritise critical datasets.

20 Virtualisation / Virtual-RAID Problems & How We Recover

1. VMFS datastore header loss – Rebuild VMFS partition map; stitch extents; mount and export VMs.

2. VMDK descriptor missing – Recreate descriptor from flat file size/geometry; reattach snapshots.

3. Broken snapshot chains (VMware/Hyper-V) – Rebuild delta hierarchy; coalesce in order; recover latest consistent state.

4. Thin-provision over-commit / 0-byte extents – Identify sparse/zeroed regions; salvage populated areas; app-level repair.

5. Hyper-V VHDX metadata corruption – Repair headers/log; map BAT; mount child differentials.

6. CSV (Cluster Shared Volumes) corruption – Rebuild NTFS/ReFS on CSV image; export VMs.

7. RDM/iSCSI LUN mapping lost – Reconstruct LUN GUID/IQN mappings; mount LUN images.

8. vSAN disk-group failure – Pull per-component objects; reconstruct objects from witnesses.

9. Ceph/RBD object loss – Collect PGs; reassemble RBD via object map.

10. Proxmox/ZFS pool won’t import – Choose last good txg; clone datasets; export VMs.

11. XenServer SR metadata loss – Rebuild SR; locate VDI chains; export disks.

12. vVols control path issues – Map vVols to base LUNs; recover guest filesystems.

13. iSCSI multipath misconfiguration – Recover from single-path image; rebuild MPIO post-recovery.

14. Storage vMotion interrupted – Resume/correct descriptor; reconcile changed blocks.

15. VM encryption (with keys available) – Decrypt at platform/API; then image disks.

16. Guest OS BitLocker inside VMDK – With recovery key, decrypt post-image and rebuild.

17. Orphaned delta files after crash – Identify newest chain by CBT/time; reattach; consolidate.

18. NFS datastore inconsistency – Stabilise NAS volume; repair export; remount datastore image.

19. Controller driver mismatch post-restore – Inject drivers; export data offline.

20. Application-consistent backups missing – Use crash-consistent set; DB/page-level repair (SQL/Exchange).

Packing & Intake

Please package drives in a padded envelope or small box, include your contact details inside, and post or drop off during business hours. For NAS/RAID servers, contact us before shipping—we’ll advise the safest way to preserve evidence and maximise recovery.

Why Leicester Data Recovery?

• 25+ years of complex RAID, NAS and virtualisation recoveries

• Per-disk hardware imaging and non-destructive virtual rebuilds

• Deep expertise in parity analysis, metadata repair and filesystem reconstruction

• Clear communication, engineer-to-engineer when needed, and accelerated options for urgent incidents

Contact Our RAID Engineers – Free Diagnostics

Tell us what happened and the array/NAS details (brand, model, drive count, symptoms). We’ll advise the safest immediate steps and start diagnostics right away.