Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a problem with my Raid setup. I have 3 disks in my Raid:

md2 : active raid5 sdc3[3](S) sdb3[4](S) sda3[0]
      2925532672 blocks level 5, 64k chunk, algorithm 2 [3/1] [U__]

md1 : active raid1 sdc2[2] sdb2[1] sda2[0]
      264960 blocks [3/3] [UUU]

md0 : active raid1 sdc1[2] sdb1[1] sda1[0]
      2102464 blocks [3/3] [UUU]

As you can see the /dev/md2 is not correctly installed in the Raid, 2 disks are not in active state.

mdadm --detail /dev/md2 gives me something like

Number   Major   Minor   RaidDevice State
   0       8        3        0      active sync   /dev/sda3
   1       0        0        1      removed
   2       0        0        2      removed

   3       8       35        -      spare   /dev/sdc3
   4       8       19        -      spare   /dev/sdb3

So there are somehow two disks in the state spare.

I tried to add them via mdadm /dev/md2 -a /dev/sdb3 and mdadm /dev/md2 -a /dev/sdc3 respectively, but I didn't work.

Do you have an idea what kind of steps I need, to get them into the Raid again?

share|improve this question
When you say "didn't work", what was the error message? Also, can you provide fdisk -l /dev/sdX output for each physical disk? – Brad May 9 '11 at 12:56
up vote 1 down vote accepted

If I'm not misreading your output, you have a RAID-5 array with two failed devices. There's no recovering from that; the array has been lost.

Delete the md device, recreate it, and restore from backups.

share|improve this answer
Yes, I've done this finally. It was a new machine so I also didn't need to care about backups and stuff. Thanks anyway. – High6 May 10 '11 at 5:40

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.