Case Study 1 — WD Elements (3.5″ HDD) Clicking / Progressive Read Failures

Issue

A WD Elements external drive began emitting repetitive seek-reset clicks yet initially remained readable. Over several weeks, error frequency increased until the volume intermittently dropped offline. A local repair shop advised a “mechanical fault” and referred the client to us.

Technical Assessment

• SMART on arrival (read-only): Pending and uncorrectable sector counts rising; reallocation events present; repeated command timeouts.

• Acoustic signature: Periodic “click–spin–click” consistent with failed head initialization / servo loss.

• Surface risk: Continued power-on while clicking likely caused secondary media abrasion and debris.

Recovery Procedure

1. Write-block intake & imaging triage

   • Captured ID, ROM, and adaptive data; prevented any host writes.

   • Head map test showed two weak heads with immediate seek error escalation on inner tracks.

2. Mechanical remediation

   • Opened the HDA under controlled lab conditions; observed head crash debris and concentric media scoring on inner zones.

   • Performed head-stack replacement (HSA) using a matched donor (same model, micro-jog family, preamp revision).

   • Transferred native ROM/adaptives to ensure proper servo alignment and defect list compatibility.

3. Service Area (SA) & translator checks

   • Read SA modules (P-list/G-list, adaptives) and rebuilt translator to restore stable LBA addressing.

4. Targeted imaging strategy (PC-3000 / DeepSpar)

   • Per-head, zone-aware imaging: read in large outer-zone spans first to maximize good yield early.

   • Aggressive soft-reset window tuning, reverse LBA passes, and head-swap bypass rules for the two weakest heads.

   • Created an error map and ran multiple low-duty retry passes only where file metadata resided.

5. Result & data validation

   • Achieved ~89% sector imaging; non-recoverable regions aligned with visibly scored tracks.

   • Reconstructed the NTFS volume; verified directory trees and opened sample client files (project folders, photos).

   • Delivered recovered content to a client-supplied external drive with hash manifests (per-file verification).

Note: Clicking = heads repeatedly failing to acquire servo; continued power can turn a fixable head issue into permanent platter damage. Early imaging dramatically improves outcome.

Case Study 2 — Dropped WD NAS (2×6 TB) in RAID 0 with On-Box Encryption

Issue

A two-bay WD NAS configured as RAID 0 (striped) was dropped during an office move. On power-up the chassis LEDs illuminated, but the unit failed to boot; faint internal clicking was audible. The array was configured with NAS-level encryption (on-box).

Technical Assessment

• Both members exhibited mechanical symptoms (clicking, intermittent ID) indicative of head damage from shock.

• Given RAID 0, 100% (or near-full) images of both members are required; any unreadable stripe segments will corrupt corresponding file regions.

• Encryption layer likely implemented as LUKS/dm-crypt or vendor on-box encryption tied to the NAS OS/keys.

Recovery Procedure

1. Safe disassembly & intake

   • Instructed client to remove the two disks from the NAS and ship drives only (no further power-ons).

   • Logged serials/slot order; preserved controller metadata where present.

2. Mechanical remediation (both disks)

   • Each HDD opened under controlled conditions; head-stack replacements performed with matched donors.

   • Verified SA modules and translators; transferred ROM/adaptives to donors.

3. Imaging (member-wise)

   • Hardware-assisted cloning with per-head maps, low-duty cycles, and adaptive timeouts.

   • Achieved full LBA images on both members (minor re-reads resolved with targeted passes).

4. Array reconstruction

   • Determined stripe size, member order, and start offsets heuristically (filesystem anchor alignment and entropy boundaries).

   • Built a read-only virtual RAID 0 from the two images; validated with filesystem structures.

5. Encryption handling

   • Identified the NAS encryption container (LUKS header/dm-crypt or vendor equivalent).

   • Using the client’s credentials/keys (and/or extracted NAS keystore), unlocked the plaintext volume and mounted the data set.

6. Extraction & verification

   • Exported shares to a 10 TB external drive; verified with path-level spot checks and per-directory hash manifests.

   • Turnaround: 4 business days end-to-end.

Note: “Platter swaps” are almost never indicated for drop damage; properly executed HSA (head) swaps are the correct remedial action in the vast majority of shock-induced clicking failures.

Case Study 3 — QNAP: Reset Array Containing Hyper-V VHDX Files (Virtual File Server)

Issue

A QNAP with 4 drives hosted a file server via Hyper-V VMs (VHDX). An ex-employee performed a factory reset, leaving the system non-functional. QNAP support could not recover the data. The appliance contained five virtual systems critical to a large print company’s operations.

Technical Assessment

• Factory resets on QNAP commonly rewrite array metadata and OS volumes, but user data blocks can remain intact.

• Typical QNAP stack: mdadm (Linux MD RAID) → optional LVM (thick/thin) → EXT4/Btrfs. Hyper-V workloads appear as VHDX files (SMB share) or as iSCSI LUNs presented to Windows.

Recovery Procedure

1. Drive-first approach

   • Cloned all four disks with hardware imagers (error-map preserved). No writes to originals.

   • Recorded residual MD superblocks and partitioning to infer prior layout.

2. Array reassembly (off-appliance)

   • mdadm forced assembly of the prior RAID set from the clones (derived level/order/chunk).

   • Activated LVM volume groups if present; mapped logical volumes without altering metadata.

3. Filesystem recovery

   • For EXT4/Btrfs: mounted read-only; when reset damaged journal/trees, used fsck (EXT4) or btrfs restore to export files even if the volume couldn’t mount cleanly.

   • Located VHDX artifacts either as files on the share or as block-backed LUNs (thin-pool volumes).

4. VHDX integrity repair

   • Validated VHDX headers/footers and BAT (Block Allocation Table).

   • Replayed VHDX log; when BAT damage existed, rebuilt block maps from extents and carved contiguous regions.

   • Mounted each VHDX as a virtual disk; repaired guest NTFS where needed via safe, image-based chkdsk/metadata reconstruction.

5. Verification & delivery

   • Brought up all five VMs to a bootable state where possible; where not, extracted complete file systems from within VHDX.

   • Delivered recovered VM directories and/or exported data with SHA-256 manifests and a brief incident report (root cause, corrective actions).

Outcome

• Full logical recovery of the VM datasets; client operations restored.

• Recommendations delivered: disable self-service reset permissions, implement off-box backups (VM-consistent), and document encryption key custody.

Final Notes

• We image first (forensic clones) and do all repair/rebuild work on copies—protecting evidence and enabling multiple strategies without risk.

• Where encryption is present (NAS on-box or SED SSD), lawful keys/credentials are required; once unlocked, recovery proceeds normally.

• Early escalation saves data: powering a clicking drive or forcing rebuilds on damaged members typically reduces recoverability.