RAID 1 problem after removing disk
Hi,
I have an odd problem with my RAID 1 (/dev/md2) setup on Debian (sid).
It used to be a 2 HDD configuration:
/dev/sdc1, /dev/sdd1
Recently sdc1 started warning me with SMART errors, so I decided to
replace it with a new drive (/dev/sde1). Perhaps foolishly, I used
gnome-disk-utility (palimpsest) to do that. I selected the RAID array,
added the new drive and it synchronised. While synchronising, the sdc
drive failed. After finished syncing, the RAID status displayed that 2
drives are fully synchronised (sdd1, sde1), one failed (sdc1) and the
array is degraded. I removed the failed disk from the array.
Next day after I started my PC i was surprised - the RAID did not start,
and was still marked as degraded. I did few checks and it seems that
mdadm 'thinks' there should be 3 drives... I can run mdadm --assemble
and it starts the array (but as degraded). How can I get rid of the
removed drive? I tried
mdadm /dev/md2 --remove failed
mdadm /dev/md2 --remove detached
they do nothing
mdadm --zero-superblock /dev/sdc1
says it couldn't open /dev/sdc1 for write (well, it could not as the
disk has died)
===================
Result from
mdadm --detail /dev/md2:
Version : 0.90
Creation Time : Wed Jun 17 21:11:25 2009
Raid Level : raid1
Array Size : 966799616 (922.01 GiB 990.00 GB)
Used Dev Size : 966799616 (922.01 GiB 990.00 GB)
Raid Devices : 3
Total Devices : 2
Preferred Minor : 2
Persistence : Superblock is persistent
Update Time : Sun Aug 14 22:23:03 2011
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 40b55130:8f1de1e6:9d4deba6:47ca997f
Events : 0.50097
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 49 1 active sync /dev/sdd1
2 8 65 2 active sync /dev/sde1
===================
cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5]
[raid4] [multipath] [faulty]
md2 : active (auto-read-only) raid1 sdd1[1] sde1[2]
966799616 blocks [3/2] [_UU]
md1 : active raid1 sda2[0] sdb2[1]
966799616 blocks [2/2] [UU]
md0 : active raid1 sda1[0] sdb1[1]
497856 blocks [2/2] [UU]
unused devices: <none>
===================
from /etc/mdadm/mdadm.conf:
# definitions of existing MD arrays
ARRAY /dev/md0 level=raid1 num-devices=2
UUID=54f1d14e:91ed3696:c3213124:8831be97
ARRAY /dev/md1 level=raid1 num-devices=2
UUID=5d97a1e5:26d9d2ed:2a031ed3:45563b24
ARRAY /dev/md2 level=raid1 num-devices=2
UUID=40b55130:8f1de1e6:9d4deba6:47ca997f
How can I get rid of the removed drive from RAID and get it fixed? I'd
be grateful for suggestions.
Kind regards,
Michal
--
Michal R. Hoffmann
Reply to: