What to Do When a Hard Drive Fails
A failed hard drive can be devastating. The data stored on the drive is often irreplaceable and critical for day-to-day operations. When a hard drive fails, it is important to act quickly and methodically to maximize the chances of recovering the data. Here are the steps I would take:
1. Stop Using the Drive
As soon as you suspect a hard drive is failing, unmount the drive and stop any activity on it immediately. Continuing to use a failing drive can further damage it and reduce the chances of data recovery.
2. Evaluate the Failure
Attempt to access the drive to evaluate the extent of the failure. If the drive is completely dead and not spinning up, the failure is likely hardware related. If the drive spins up but is not accessible, the failure may be logical and related to the file system or partitions.
3. Choose a Recovery Method
For a mechanical failure, choose a professional data recovery service. For logical failures, you may be able to run recovery software yourself. The approach depends on the cause of failure.
Professional Data Recovery Services
For mechanical failures related to the physical hard drive components, professional data recovery services offer the best chance of recovering data.
1. Find a Reputable Service
Research and select a reputable recovery service with experience, capabilities and cleanroom facilities suited to your drive. Beware of services making unrealistic claims.
2. Protect the Drive
Package the failed drive securely to prevent further damage in transit to the recovery facility. Avoid exposing the drive to shock, static electricity or temperature extremes.
3. Get an Evaluation
The recovery service will perform an initial evaluation to determine the failure and probability of recovering data. This helps set expectations.
4. Attempt Recovery
If recovery looks hopeful, authorize the service to proceed. The techniques used will depend on the drive failure, and could include:
- Head swaps – replacing failed read/write heads
- Drive imaging – imaging accessible areas of the drive
- Transplanting platters – transplanting platters to a working drive
- Reverse engineering – manually recovering raw data
5. Preserve Recovered Data
Once data is recovered, immediately back it up to new media. Then verify the integrity and usability of the recovered files.
DIY Software Recovery Methods
For logical recoverable failures caused by file system corruption or deleted files, recovery software offers a more affordable DIY option.
1. Select the Right Tools
Research recovery software suited to the drive file system – for example, Recoverit for FAT/NTFS, Disk Drill for Mac HFS+. Avoid software requiring drive installation.
2. Create a Clone
Use disk imaging software like ddrescue to create a complete sector-by-sector clone or image file of the failing drive before attempting recovery. This preserves the drive state.
3. Scan the Clone
Run the recovery software to scan the disk image for recoverable files. This may take hours for a large drive. The software reconstructs file system metadata to regain access.
4. Recover Files
Preview and selectively recover needed files and folders. Avoid mass recovery of everything, as this mixes garbage data with good data. Recover files to a different healthy drive.
5. Check Recovery Completeness
Verify recovered files open and contain expected data. The condition of the failed drive affects recoverability – expect partial recovery.
Common Hard Drive Failure Causes
Understanding the common causes of drive failure can help avoid data loss:
- Mechanical failure – motor, head or platter failures caused by wear and tear or shock.
- Logical failure – corruption of file system or partitions from unexpected shutdowns, drive errors, viruses, bugs or user errors.
- Bad sectors – unreadable areas on the platters caused by physical media defects. The drive remaps sectors automatically until failure.
- Firmware issues – bugs or power surges corrupting the drive’s controller/firmware.
- Electronics failure – problems with circuit boards or components usually diagnosed by swapping boards.
Prevention is ideal, so protect drives from shock, maintain proper ventilation and replace drives periodically. But if disaster strikes, act quickly because time is of essence for successful data recovery!
