Well, after having my RAID array (RAID 5 on four external firewire disks) working very nicely for a while, I did a reboot last night, and when the system came back up, it started complaining that it only recognized two of the four disks as being part of the array. Trying to force the other two disks using mdadm resulted in a message that there was no RAID superblock on those disks.

Is there anyway to tell mdadm to rebuild the superblock on those drives and add them back to the array? Or to get mdadm to rebuild the array without wiping all my data?

Thanks,
Ewan

Looking through everything I could find online about trouble-shooting Linux RAID (and there isn't much - especially compared with the wealth of info on how to setup RAID), it looks like I might be able to upgrade my version of mdadm and use --update=summaries to fix my problem.

Has anyone successfully done this? Or is there something else I need to look at?

Thanks,
Ewan