I'm planning out a 5-20 drive RAID array (to be grown as needed by adding more drives) and have been considering ways to integrate a 'spare' drive in one or more of the non-hotswap bays available in the chassis. Would it be reasonable to do the following?
- Assemble each 'hot swap' bay as a 'device + missing' RAID-1.
- Assemble the RAID-5/RAID-6 from the RAID-1 slots, leaving the 'cold swap' drive out.
- On failure, add the 'cold swap' drive into the 'missing' slot of the affected RAID-1 with a script.
Theory behind this is that it allows the rebuild to begin immediately, without requiring to wait for the rebuild to finish before the failed drive can be hot-swapped. Once the hot-swap drive is replaced and the rebuild finished + mirrored back in, the 'cold swap' drive can be pulled back out of the appropriate RAID-1.
Or is there a more efficient way to implement this idea of allowing for cold-swap versus hot-swap status for drives in a RAID array? Or would the RAID-1 coming back up in this manner cause problems with the RAID-5/RAID-6 wrapped around it?