I'm building an Ubuntu 10.04 virtual machine server. I have three 500GB SATA drives which I setup in a RAID5 configuration. The setup went fairly easily and I installed the OS without a problem.
Before I start setting everything up, I want to make sure that if I lose one of the drives I know how to recover. For my dry run, I removed one of the drives, connected it to my laptop with a SATA USB docking station, and deleted the partitions from it.
I physically reinstalled the drive in my server and tried to boot. During boot I'm prompted to start the degraded RAID. I say yes to that and I get the following:
mdadm: CREATE user root not found
mdadm: CREATE group disk not found
raid5: raid level 5 set md0 active with 2 out of 3 devices, algorithm 2
mdadm: /dev/md0 has been started with 2 drives (out of 3)
raid5: failed to run raid set md1
mdadm: failed to RUN-ARRAY /dev/md1: Input.output error
mdadm: Not enough devices to start the array while not clean - consider --force
Started the RAID in degraded mode
Gave up waiting for root device:
*then a list of common problems and then:
ALERT! /dev/disk/by-uuid/bunchanumbersnad letters does not exist. Dropping to a shell!
Then I get a busybox shell and a prompt of "initramfs".
So, the question is, how would I go about rebuilding the third drive in the array? Can I boot to a live CD and do something there? Is there something I can do at the initramfs prompt?
Glad I'm not trying to figure this out on a failed production box! Yay for dry runs! :P
Thanks in advance for any help.