degraded RAID array on squeeze

[Milos Negovanovic <milos.negovanovic@gmail.com>]

Hi all,

one of my servers has experienced degradation in one of its RAID arrays:

root@micro ~ # cat /proc/mdstat 
Personalities : [raid1] 
md2 : active raid1 sda3[0]
1424121720 blocks super 1.2 [2/1] [U_]
            
md1 : active raid1 sda2[0] sdb2[1]
29295544 blocks super 1.2 [2/2] [UU]
		        
md0 : active (auto-read-only) raid1 sda1[0] sdb1[1]
11716536 blocks super 1.2 [2/2] [UU]
			            
unused devices: <none>


Following some online tutorials for RAID array recovery Iam trying to
re-insert /dev/sdb3 into /dev/md2:

root@micro ~ # mdadm --add /dev/md2 /dev/sdb3
mdadm: add new device failed for /dev/sdb3 as 2: Invalid argument

As you can see it fails to re-insert the component! Whats suspicious is
that /dev/sdb1 and /dev/sdb2 are just fine in other 2 RAID components,
so I don't think that the /dev/sdb drive has failed!

Any suggestions are welcome!

Regards
-- 
Milos Negovanovic
milos.negovanovic@gmail.com