Server Recovery & Rescue
RAID Failure Recovery
RAID protects against single-disk failure, until a second disk fails during rebuild, the controller dies, or silent corruption spreads. RAID recovery means correct failure diagnosis, safe rebuild sequencing, and honest assessment of when to stop and restore from backups instead.
Key points
- Identify the true failure: disk, controller, cable, or configuration.
- Never force-online multiple foreign drives without imaging first.
- Replace with matching spec drives; monitor rebuild progress closely.
- Watch for UREs during large RAID5/6 rebuilds, have backups ready.
- Prefer RAID6/RAID10 for large spinning disks; RAID5 is obsolete there.
- Monitor SMART and schedule patrol reads/scrubs to catch decay early.
- Keep hot spares on critical arrays to shrink degraded windows.
- Remember: RAID is uptime, backups are recovery, maintain both.
Field note
During big RAID5/6 rebuilds, watch for unreadable sectors like a hawk, a second failure mid-rebuild is how arrays die, and it's exactly when backups earn their keep.
Frequently asked questions
Can data survive two dead disks in RAID5?
No, that's beyond its design. Recovery then means professional lab work or backups.
How long does a rebuild take?
Hours to days depending on size and load; arrays stay vulnerable throughout.
Should we use hardware or software RAID?
Both work; software RAID (mdadm) offers portability, hardware offers battery-backed cache. We match to workload.
When do you stop repairing and restore?
When repair risks exceed restore time, a judgment call made with backup status in hand.
How Kinetikatech helps with server recovery & rescue
You shouldn't have to become an expert in server recovery & rescue: Emergency response for hacked, corrupted, or failed servers: isolation, diagnosis, restoration, and hardening. That's exactly what Malware Removal & Cleanup and Server Management is for, setup, hardening, monitoring, and a human on call day and night.