Norwich Data Recovery — No.1 RAID 1 Recovery Specialists

25+ years’ RAID experience. We recover mirrored arrays for home users, SMEs, enterprises and public-sector teams—from simple 2-disk mirrors to complex multi-mirror sets in racks and NAS fleets. Free diagnostics and clear options before any work begins. Best-value, engineering-led recoveries.

Key fact: RAID 1 mirrors data identically across members. It has no parity; integrity depends on both drives holding consistent copies. Recovery focuses on stabilising each member, producing verified clones, then virtually re-mirroring and repairing the filesystem.

Platforms We Handle

• Software mirrors: Windows Dynamic Disks, mdadm/LVM (Linux), Apple CoreStorage/APFS (legacy stripe+mirror combos), Storage Spaces Mirror.

• Hardware mirrors: Dell PERC, HPE SmartArray, LSI/Broadcom, Adaptec/Microchip, Areca, Intel RST/Matrix.

• NAS mirrors: Synology SHR-1, QNAP static RAID 1, Netgear ReadyNAS, WD, Buffalo, Asustor, TerraMaster, Lenovo/Iomega, TrueNAS.

• Filesystems: NTFS, ReFS, exFAT, FAT32, ext2/3/4, XFS, Btrfs, ZFS (mirrored vdevs), HFS+, APFS.

• Media: 2.5″/3.5″ HDD, SATA/NVMe SSD (M.2/U.2), SAS, USB-bridged externals.

Top 15 NAS / External RAID Brands in the UK & Popular Models

(Common deployments we see—if yours isn’t listed, we still support it.)

1. Synology — DS224+, DS423, DS723+, DS923+, RS1221+

2. QNAP — TS-251D/TS-262, TS-453D, TS-464, TVS-h674

3. Netgear ReadyNAS — RN212/RN214, RN424, RN524X

4. Western Digital (WD) — My Cloud EX2 Ultra, PR2100/PR4100

5. Buffalo — LinkStation LS220D, TeraStation TS3410DN/5410DN

6. Asustor — AS1102T (Drivestor 2), AS5202T, AS5304T

7. TerraMaster — F2-221, F2-423, F4-423 (mirror on multi-bay)

8. LaCie (Seagate) — 2big/6big (often configured as RAID 1 for safety)

9. TrueNAS / iXsystems — Mini X/X+, R-series (mirrored vdev pools)

10. Lenovo/Iomega (legacy) — ix2-DL, PX2-300D

11. Seagate — BlackArmor NAS 220, Business Storage 2-Bay (legacy)

12. Zyxel — NAS326, NAS542

13. Drobo — 5N/5N2 (BeyondRAID; mirror-like redundancy modes)

14. Promise — VTrak N-/E-class (as NAS back-ends)

15. OWC — ThunderBay (host-managed mirrors), Aura/Envoy enclosures

Top 15 Rack/Server Platforms Common with RAID 1 (and Popular Models)

1. Dell EMC PowerEdge — R250/R350 (OS mirror), R650/R750

2. HPE ProLiant — DL360/DL380 Gen10/Gen11 (OS/data mirrors)

3. Lenovo ThinkSystem — SR630/SR650

4. Supermicro — 1029/2029/6029 (OS mirror on SATADOM/SSD)

5. Cisco UCS — C220/C240 M5/M6

6. Fujitsu PRIMERGY — RX2530/RX2540

7. Inspur — NF5280M6/M7

8. QCT (Quanta) — D52B-1U / D52BQ-2U

9. ASUS Server — RS520/RS700

10. Tyan — Thunder/Transport 1U/2U

11. IBM System x (legacy) — x3550/x3650 M4/M5

12. Areca (controller deployments) — ARC-1883/1886 series

13. Adaptec by Microchip — SmartRAID 31xx/32xx in varied chassis

14. NetApp/Promise JBODs — OS mirrors on controller hosts

15. Intel (legacy) — R2000/R1000 platforms with RSTe mirrors

Our Professional RAID 1 Recovery Workflow

1. Intake & Free Diagnostic

   • Capture controller/NAS metadata, disk order/slots, logs and SMART; document evidence chain if required.

2. Image Each Member (Never Work on Originals)

   • Hardware imagers with per-head zoning, timeout budgeting, ECC controls.

   • SSD/NVMe: read-retry/voltage stepping, thermal control; controller-dead → chip-off + FTL reconstruction.

3. Virtual Mirror Rebuild

   • Analyse divergence between members (which copy is newer/consistent), align LBAs/offsets, normalise sector sizes (512e/4Kn), and build a virtual mirror over the cloned images.

4. Filesystem Repair & Export

   • Repair superblocks, journals and B-trees (NTFS $MFT/$LogFile, APFS checkpoints/omap, ext4 backup superblocks, Btrfs/ZFS checksums).

   • Mount read-only and export validated data.

5. Verification & Delivery

   • Per-file hashing (MD5/SHA-256), sample tests, secure hand-off (encrypted drive or secure transfer). Optional recovery report.

Overwrites: Blocks genuinely overwritten (e.g., long-running writes after a fault) cannot be restored. We target pre-overwrite regions, snapshots, journals, replicas and unaffected systems.

Top 40 RAID 1 Errors We Recover — With Technical Approach

Format: Issue → Diagnosis → Lab Recovery (on clones/virtual mirror)

1. Single drive mechanical failure → SMART/terminal, head current traces → Donor head-stack + ROM adaptives; low-stress imaging; mirror from the good member.

2. Both drives failed at different times → Error heatmaps/date codes → Image each; choose per-LBA best sector; assemble composite virtual member against the healthier image.

3. SSD controller death on one member → No enumerate/loader → Chip-off per-die dumps; FTL rebuild (BCH/LDPC, XOR/scrambler, interleave); integrate image.

4. PMIC/LDO failure (SSD) → Rail collapse → Replace PMIC; if controller still dead, proceed to chip-off.

5. Retention loss / read-disturb (TLC/QLC SSD) → Unstable reads → Temp-controlled imaging; voltage stepping/read-retry matrices; majority vote of multiple passes.

6. Bad sectors on HDD member → Concentrated error bands → Head-map imaging with skip windows; use intact mirror copy to fill gaps.

7. Preamp failure (HDD) → Abnormal head bias → HSA swap; conservative imaging; rebuild mirror from good side.

8. Translator corruption (HDD) → Vendor logs show LBA↔PBA faults → Rebuild translator or compute synthetic mapping; image then re-mirror.

9. ROM/adaptives loss (HDD) → SPI dump missing → ROM transplant; adaptives (head map/micro-jog) restored; image.

10. USB/Thunderbolt bridge failure → Drive OK bare, not in enclosure → Bypass bridge; image raw drives; reconstruct mirror.

11. 3.3 V pin-3 behaviour (WD) → Doesn’t spin in enclosure → Isolate pin/apply correct PSU; image and proceed.

12. Write-hole from sudden power loss → Divergent last-writes between members → Choose consistent member using journal/log comparison; replay filesystem logs on that basis.

13. Out-of-sync mirror after degraded run → Silent divergence → Per-block comparison; trust copy with coherent metadata (superblocks, journal heads).

14. Wrong disk reinserted (older epoch) → Mixed generations → Epoch/timestamp analysis; exclude stale member; rebuild from newest good image.

15. Cross-connect during swap (members swapped) → Controller labels inverted → Ignore controller, use slot history + content signatures to map correct roles.

16. Automatic rebuild onto failing spare → New spare has weak media → Image both old and new; construct composite from best sectors; stop further destructive rebuilds.

17. Controller cache write-back loss → Incomplete metadata commits → Prefer member with complete journal; run controlled log replay on the assembled image.

18. mdadm superblock corruption → Superblock variants disagree → Select highest consistent event count; assemble virtual mirror manually.

19. Windows Dynamic Disk mirror DB damage → LDM corrupt → Recover LDM from backup locations; if absent, infer from partition/FS signatures.

20. Storage Spaces mirror metadata loss → Pool won’t mount → Rebuild slab map; export virtual disk read-only; repair guest FS.

21. APFS container divergence → Checkpoint/omap mismatch → Walk checkpoint history; pick latest coherent checkpoint; mount read-only.

22. HFS+ catalog/extent damage → B-tree errors → Rebuild trees on image; carve allocator patterns for partials.

23. NTFS $MFT/$LogFile corruption → Dirty shutdown → Replay log; rebuild MFT entries; relink orphans.

24. ReFS integrity stream mismatch → Copy-on-write artefacts → Prefer blocks with valid checksums; export verified files.

25. ext4 superblock/inode table loss → Use backup superblocks; offline fsck-like rebuild on image.

26. XFS log corruption → Manual log replay on mirror image; directory rebuild.

27. Btrfs mirrored metadata errors → Superblock triplet voting → Select best pair/root; recover subvolumes/snapshots.

28. ZFS mirrored vdev member loss → Pool won’t import → Import with rewind/readonly; scrub; zdb-assisted file export from good side.

29. BitLocker/FileVault on mirror → Encrypted volumes → Full-disk image; valid key required; decrypt and export read-only.

30. Controller NVRAM reset → Mirror membership forgotten → Infer mapping from content; avoid “initialise”; re-establish virtual mirror.

31. Sector-size mismatch (512e vs 4Kn) → Refuses to mount → Normalise sector size in virtual model; repair FS structures.

32. SMART trip then sudden death on second member → Minimal reads → Fast-first imaging for easy sectors; targeted re-reads; base mirror on healthier copy.

33. Hot-plug dropped link (SATA CRC errors) → Intermittent timeouts → Replace cabling/backplane after imaging; small-block PIO-like imaging.

34. NAS OS migration (Synology↔QNAP) → Metadata/layout differences → Parse md/LVM/Btrfs maps directly; no in-place repairs; assemble mirror virtually.

35. User “chkdsk /f” on broken mirror → Additional damage → Roll back to pre-repair image; journal-aware recovery; ignore destructive fixes.

36. Accidental re-initialisation / quick format → Partition/boot sectors overwritten → Rebuild partition table from backups/FS headers; restore directory structures.

37. Accidental member removal / re-order → Wrong member active → Identify correct current member by journal continuity; rebuild with that image.

38. NAS snapshot deletion during incident → Lost easy rollback → Low-level copy-on-write parsing (Btrfs/ZFS) to harvest surviving extents.

39. CCTV/NVR volumes on mirrors “overwritten” → Circular overwrites → Focus on pre-overwrite regions, DB indices, and off-box replicas/cloud; explain hard limits.

40. Firmware bug causing LBA remap on one member → Misaligned bands → Build corrective translation layer for that image; re-align mirror and repair FS.

Why Choose Norwich Data Recovery

• 25 years in business with thousands of successful RAID/NAS recoveries

• Multi-vendor expertise across controllers, NAS OSs, filesystems and HDD/SSD/NVMe media

• Advanced tooling & donor inventory to maximise recovery outcomes

• Free diagnostics with clear options before any paid work begins

• Optional priority turnaround (~48 hours) where device condition allows

Speak to an Engineer

Contact our Norwich RAID 1 engineers today for a free diagnostic. We’ll stabilise your members, rebuild the mirror virtually, and recover your data with forensic-grade care.