Make Backups Before and During RAID Rebuilds
Rebuilding is designed to be a procedure of near-last resort, so you shouldn’t rely on it to solve all of your problems. If you’re smart, then you’ll create a regular system task that backs up your RAID array periodically so that you don’t lose too much if it fails.
You should also back up all of the disks in the RAID array before attempting a rebuild. Ensure that you label each backup clearly so that you can maintain the proper order if you need to reconstruct the volume from these reserves.