On 28/05/13 09:04, Mark Rogers wrote:
I'm having problems understanding what is happening on my RAID array.
$ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sda1[0] sdb1[1](F) 976629568 blocks super 1.2 [2/1] [U_]
To me, that suggests that sdb has failed,
That's the way I would interpret it too. mdadm says sdb1 has failed, so it's not using it. I googled, and found http://ubuntuforums.org/showthread.php?t=1677577 which lead me to http://unthought.net/Software-RAID.HOWTO/Software-RAID.HOWTO-6.html#ss6.2 and http://tldp.org/FAQ/Linux-RAID-FAQ/x37.html#failrecover
however, syslog contains lots of errors on sda but no mention of sdb.
Perhaps it's not using it any more, so it doesn't show up.
[SNIP]
Should I conclude that both disks have failed?
If you're getting error messages for sda then there may well be a fault. sdb may well be faulty too, as it's marked as faulty.
What is the best route to recovery here?
Before doing anything else, BACK EVERYTHING UP. Check everything backed up, and check that you can read the backup.
Ie which disk do I swap out first with a new disk? Logically swapping out sda is the only thing that makes sense to me but advice welcomed.
NO!!!!!! if sdb is marked as failed, mdadm won't be using it. The only drive with data on will be sda. If you swap it out, you'll have nothing left.
TBC
Steve