mdadm - Recovering a 'split' RAID1 array

Posted by Hamza on Server Fault See other posts from Server Fault or by Hamza
Published on 2012-11-04T15:57:19Z Indexed on 2012/11/04 17:03 UTC
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linux

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raid

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mdadm

I have two drives that used to be part of a single RAID1 volume but it appears that one of them went offline for some time, something I've noticed just now when I rebooted my system.

I now seem to have two RAID volumes, as reported by:

# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md126 : active raid1 sdc[1]
      2096116 blocks super 1.2 [2/1] [_U]

md127 : active (auto-read-only) raid1 sdb[0]
      2096116 blocks super 1.2 [2/1] [U_]

unused devices: <none>

Not exactly sure where to go from here. How can I merge and re-sync these volumes without data loss?

Thanks.

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