A drive dropped out of my raid 5 array yesterday. It looks like the reason was due to a bad controller so I switched it out and attempted to re-add the drive but mdadm claimed it couldn't do it. So I zerod the superblock and just added the drive normally and left it to resync.
When I came to check on the array this morning I was unable to mount it at all and it's now showing as CLEAN FAULTY with two drives missing. The two missing drives are listed as spare and faulty spare.
Is there anything I can do in this situation or is the array gone?
The disks appear to be fine - except maybe for enough bad data on one of the disks for mdadm to get annoyed and kick that disk from the array too.
I was able to recreate the array by marking the disk as working and forcing the assembly so I'm currently just making sure that all my backups are up to date.
So I can probably change this question to: RAID5 seems to be a problem with large disks (3x3TB). I'm considering changing to mirrored RAID-Z arrays but is there anything else I should consider instead?