Leicester Data Recovery – Wales’ No.1 RAID 1 Data Recovery Specialists (25+ Years)

With over 25 years’ experience, Leicester Data Recovery recovers mirrored arrays for home users, SMEs, large enterprises and public-sector teams across Leicester, Coventry, the Midlands. We handle software and hardware mirrors, NAS and rack servers, external multi-bay enclosures and direct-attach arrays.

Note: RAID 1 has no parity and no striping; it uses mirrored copies. Many “RAID issues” you may read about (e.g., parity-drive failure) don’t apply to RAID 1. Our workflow is built around that reality.

Platforms & File Systems We Handle

• Array types: RAID 1 (2–32-disk mirrors), nested mirrors (e.g., RAID 10 mirrorsets), mdadm/LVM mirrors, Windows Dynamic Disk mirrors, Storage Spaces two-way mirrors, Btrfs/ZFS mirrors, NAS “Basic/SHR-1 style” mirrors.

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

• Controllers / software: Broadcom/LSI MegaRAID, Adaptec/Microchip, Areca, Dell PERC, HPE Smart Array, Intel RST/VROC, Synology/QNAP mdadm, TrueNAS/ZoL.

• Encryption (lawful, with keys): BitLocker, FileVault, LUKS, VeraCrypt.

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 PR4100, EX2 Ultra, 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).

10. ioSafe (Synology-based) – 218/1522+ derivatives.

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

12. Drobo (legacy) – 5N/5N2, B810n.

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

14. Zyxel – NAS326, NAS540.

15. D-Link – DNS-320L, DNS-340L.

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

15 Rack-Server Vendors Used for RAID 1 (with example models)

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

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

3. Lenovo – ThinkSystem SR650/SR630, SR645.

4. Supermicro – SuperServer 2029/6029/1029 families.

5. Fujitsu – PRIMERGY RX2540/RX2520.

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

7. Gigabyte Server – R272/R282 series.

8. ASUS Server – RS520/RS720, ESC workstations.

9. Tyan – Thunder/Transport 1U/2U ranges.

10. QCT (Quanta) – D52BQ/D43K series.

11. Inspur – NF5280M6/M7.

12. Huawei – FusionServer Pro 2288H.

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

14. Intel (legacy platforms) – S2600-based racks.

15. Apple (legacy) – Mac Pro racks with DAS HBAs (ATTO/Areca).

Our Professional RAID 1 Recovery Workflow

1. Evidence-safe intake & per-disk imaging – Hardware imagers (PC-3000, Atola, DeepSpar) with head maps, adaptive timeouts and power-cycle strategies; never operate on originals.

2. Member analysis – Identify the most complete/least-error mirror member; detect stale vs current copies, metadata/skew and bad-block maps.

3. Virtual reconstruction – Assemble a read-only virtual mirror from images; when needed, selectively prefer sectors from the healthier member.

4. File-system repair – Read-only mount/repair NTFS/ReFS/APFS/ext4/XFS/Btrfs/ZFS; replay journals; rebuild trees; carve if necessary.

5. Verification & hand-over – Hash checks, spot-open key files, structured delivery.

40 RAID 1 Errors We Recover From – With Technical Recovery Notes

Key concept: In RAID 1, the priority is selecting the best member (or best sector from each member) and avoiding writes that could destroy the last good copy.

Geometry / Metadata / Controller

1. Unknown mirror composition – Fix: inspect controller/mdadm metadata, WWN/serials, timestamps; identify the authoritative member.

2. Controller NVRAM reset (lost config) – Fix: ignore volatile config; read on-disk superblocks; assemble mirror virtually.

3. Foreign import mismatch – Fix: discard “foreign” metadata; rebuild from raw images; verify by FS consistency.

4. Controller swap between models – Fix: bypass controller; rely on on-disk metadata and FS anchors.

5. Mixed sector size (512e/4Kn) – Fix: normalise sector size in images; re-assemble with consistent geometry.

6. HPA/DCO on one member – Fix: detect hidden ranges; virtually remove HPA/DCO to equalise capacities.

7. Capacity mismatch members – Fix: trim larger image to smallest common LBA to regain consistent mirrors.

8. Write-cache tear on power loss – Fix: trust member with clean journal; replay FS logs; reconcile dirty regions cautiously.

9. Metadata version drift (mdadm/Intel RST) – Fix: prefer newest consistent superblocks; hand-edit fields if needed; assemble read-only.

Member Disk Failures / Media Problems

10. One member fully dead – Fix: invasive imaging (head-map, donor heads if required); use survivor as primary; fill gaps from recovered sectors.

11. Both members degraded – Fix: per-LBA “best-of” merge across images; maximise continuity for FS repair.

12. Bad-sector storms on one member – Fix: multi-pass soft→hard reads; skip/late-fill; trust healthy copy where overlapping.

13. HDD head degradation – Fix: selective head imaging; throttle duty cycle; donor head swap only if necessary.

14. SSD uncorrectables (NAND wear/retention) – Fix: ECC-aware reads, voltage/temperature tuning, soft decoding; prefer healthier member.

15. NVMe link instability – Fix: lock lanes/speeds; reset sequences; direct HBA capture.

16. SAS expander/backplane faults – Fix: move each member to stable HBA ports; image independently.

17. USB-SATA bridge failure in mirrored DAS – Fix: bypass bridge; if hardware-encrypted, repair/match bridge before imaging.

Human Errors / Operational

18. Wrong disk removed from mirror – Fix: identify “good” by serial/SMART and FS freshness; rebuild virtually from good image.

19. Accidental initialise/new mirror created – Fix: historical FS remains; scan for prior partition/FS anchors; recover previous dataset.

20. Rebuild to the wrong (stale) disk – Fix: use images taken before the rebuild; choose the freshest as base; discard stale.

21. Clone written over good member – Fix: salvage from other member; carve for overwritten areas if partial.

22. Members swapped between bays – Fix: re-associate by serials and controller port history; assemble virtually.

23. OS reinstalled on mirror – Fix: deep scan for previous FS; reconstruct trees; export user data.

24. Member hot-added with silent mismatch – Fix: detect block-level divergence; prioritise consistent copy; blocklist divergent regions.

Rebuild / Resync Behaviour

25. Resync aborted mid-way – Fix: image both; pick newest coherent regions; resume virtually from last consistent LBA.

26. Bitmap-based resync errors (mdadm) – Fix: ignore bitmap; perform full compare/merge from images; then FS repair.

27. Controller forced rebuild on marginal disk – Fix: stop; image marginal disk first; use it only where necessary.

28. Background patrol read triggers second failure – Fix: halt; image both immediately; reconstruct best-of map.

File System on Top of RAID 1

29. NTFS $MFT/$MFTMirr corruption – Fix: rebuild from mirror and $LogFile; recover orphans.

30. ReFS metadata damage – Fix: salvage block-cloned data; export intact objects; repair catalogues.

31. APFS container/volume tree corruption – Fix: parse checkpoints; rebuild B-trees; restore volume groups; recover user space.

32. HFS+ catalog/extent failures – Fix: rebuild from extents + journal; re-link directory hierarchy.

33. ext4 superblock/journal loss – Fix: use alternate superblocks; replay journal; inode table rebuild.

34. XFS log corruption – Fix: xlog replay; inode btree/dir leaf repair.

35. VMFS datastore header loss on mirrored LUN – Fix: reconstruct partition map; stitch extents; mount VMFS and export VMs.

36. exFAT on mirrored DAS – Fix: rebuild VBR/BPB, allocation bitmap and directory entries; fix large video containers.

Software Mirrors / NAS / OS-Level

37. Windows Dynamic Disk mirror broken – Fix: mount each member image independently; mark foreign disk online in a clone; export data.

38. Storage Spaces two-way mirror failed – Fix: read-only mount from pool metadata; identify healthy slabs; rebuild virtual disk; extract.

39. Btrfs RAID1 metadata/data imbalance – Fix: reconstruct chunk/extent trees; mount read-only; export subvolumes/snapshots.

40. ZFS mirror won’t import – Fix: read labels; choose last good txg; import read-only; send/receive clean snapshots or export files.

What We Recover From (Hardware & Brands)

• Drives commonly found in mirrors: Seagate, Western Digital (WD), Toshiba, Samsung, HGST, Crucial/Micron, Kingston, SanDisk (WD), ADATA, Corsair, Fujitsu, Maxtor (legacy) and others.

• Appliances & HBAs: Dell EMC, HPE, Synology, QNAP, NetApp, WD, Seagate/LaCie, Buffalo, Drobo (legacy), Netgear, Lenovo, Intel, ASUS, Promise, IBM, Adaptec/Microchip, Areca, Thecus—among others.

Packaging & Intake

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

Why Leicester Data Recovery?

• 25+ years of RAID and multi-disk recoveries

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

• Deep expertise in mirror selection/merge, controller metadata analysis and file-system reconstruction

• Clear engineer-to-engineer communication and accelerated options for urgent cases

Contact Our RAID 1 Engineers – Free Diagnostics

Tell us what happened (brand/model, drive count, symptoms, any changes attempted). We’ll advise the safest next step immediately.