First steps after a RAID failure
Preserve drive order and configuration after a RAID warning. An unverified rebuild or initialisation can put data at further risk.
Record the state before making changes
Degraded and crashed are different states. A degraded array may remain accessible with reduced protection; a crashed volume may be unavailable. Capture the status, drive numbers and error messages. Do not try to dismiss a warning by removing drives or creating a new array.
Preserve the drive order
Limit new writes and preserve existing configuration information. Do not swap drives around. Before shutting down or removing a drive, check the procedure for the exact system. Neither immediate shutdown nor immediate rebuilding is a safe universal instruction.
- Record each drive's slot and serial number.
- Note the sequence of failures and recent changes.
- Do not initialise or force a rebuild without verifying the situation.
A rebuild is not guaranteed recovery
A rebuild is not a general repair tool for damaged files. Its suitability depends on the remaining drives, RAID level and backup availability. Do not casually interrupt a procedure already in progress either. Multiple suspect drives or an unclear failure history warrant specialist assessment before the next action.
RAID does not replace a backup
Array redundancy does not protect against accidental deletion or every type of failure. Keep a separate backup and test restoration. Provide the service team with the controller or NAS model, full drive inventory and date of the last available copy. Recovery prospects depend on the actual failure, not just the number of drives.
Further reading
This article is a general guide. Follow the manufacturer’s instructions for your particular device.
