RAID Rebuild Guide
Expert guidance for rebuilding failed RAID arrays. Follow our step-by-step process or contact our 24/7 RAID recovery specialists for immediate assistance.
RAID Emergency Hotline: 020 7237 6805RAID Rebuild Warning
Improper RAID rebuild attempts can cause permanent data loss. If your data is critical, contact professionals before attempting any rebuild.
RAID Levels and Rebuild Considerations
Different RAID levels require specific approaches during rebuilds. Understand your configuration before proceeding:
RAID 0
No redundancy - single drive failure means total data loss. Professional recovery often only option.
RAID 1
Mirrored drives - replace failed drive and rebuild from mirror. Most straightforward rebuild.
RAID 5
Single parity - replace failed drive and rebuild using parity data. High stress on remaining drives.
RAID 6
Dual parity - can survive two drive failures. Rebuild process similar to RAID 5 but more complex.
RAID 10
Mirrored stripes - replace failed drive and rebuild from its mirror. Faster rebuild than RAID 5/6.
Other Arrays
RAID 50, 60, proprietary arrays - require specialized knowledge. Professional help recommended.
RAID Rebuild Step-by-Step Guide
Follow these steps carefully to maximize your chances of successful RAID rebuild:
Assess the Failure
Determine the exact nature of the RAID failure:
- Check RAID controller status/messages
- Identify which drives have failed
- Note any unusual sounds from drives
- Check SMART status of all drives
Critical: If multiple drives show problems, stop immediately and contact professionals.
Prepare for Rebuild
Essential preparations before starting rebuild:
- Backup all accessible data if possible
- Use identical replacement drive (same make/model/size)
- Ensure stable power supply (UPS recommended)
- Document current configuration
- Check controller battery/cache status
Note: Rebuilds can take many hours to days for large arrays.
Initiate Rebuild
Steps to start the rebuild process:
| Controller Type | Rebuild Method | Estimated Time |
|---|---|---|
| Hardware RAID | Use controller BIOS/utility to mark drive as failed and start rebuild | 2-24 hours per TB |
| Software RAID | Use OS utilities (mdadm for Linux, Disk Management for Windows) | 4-48 hours per TB |
| NAS Devices | Use web interface to replace drive and initiate rebuild | 6-36 hours per TB |
Tip: Never interrupt a rebuild process - this can cause complete array failure.
Post-Rebuild Verification
After rebuild completes, verify integrity:
- Data check: Scan for corrupted files
- Performance test: Verify normal operation
- SMART check: Monitor all drives for problems
- Backup: Immediately backup critical data
- Monitor: Watch for subsequent failures
Warning: RAID arrays often fail completely soon after first failure. Have a backup plan.
RAID Rebuild Success Rates by Configuration
Our recovery statistics for different RAID scenarios:
| RAID Level | Single Drive Failure | Multiple Drive Failure | Controller Failure | Reboot During Rebuild |
|---|---|---|---|---|
| RAID 0 | 0% | 0% | 85-95% | 0% |
| RAID 1 | 98% | 50% | 90-98% | 80% |
| RAID 5 | 95% | 30% | 85-95% | 40% |
| RAID 6 | 97% | 75% | 90-97% | 60% |
| RAID 10 | 99% | 60% | 92-98% | 70% |
Need Professional RAID Recovery Assistance?
Our RAID specialists are available 24/7 to help with failed rebuilds and data recovery.