Unable to resolve UUID for RAID after reboot

jming · 06-19-2012, 03:06 AM

Hi,

My Linux machine has two hard disks configured as Raid0 (Stripe). But the RAID cannot be recognized after machine reboot. When booting, the machine shows error messages during filesystem checking:

Code:

fsck.ext4: Unable to resolve 'UUID=<uuid1>'
fsck.ext4: Unable to resolve 'UUID=<uuid2>'
fsck.ext4: Unable to resolve 'UUID=<uuid3>'

There are three filesystems with the resolvable UUID problem (that is, <uuid1>, <uuid2>, and <uuid3>).

I used blkid command to check the filesystem:

Code:

/dev/sda1: UUID="xxxxxxxxxxxxxxxxxxxxxxx" TYPE="ext4"
/dev/sda2: UUID="xxxxxxxxxxxxxxxxxxxxxxx" TYPE="ext4"
/dev/sdb1: UUID="xxxxxxxxxxxxxxxxxxxxxxx" TYPE="swap"
/dev/sdb2: UUID="xxxxxxxxxxxxxxxxxxxxxxx" TYPE="ext4"
/dev/sdc: TYPE="isw_raid_member"

The first four UUIDs for the other filesystems are OK, but the <uuid1>, <uuid2>, and <uuid3> with the unresolvable UUID problem are not displayed in the output of blkid.

I checked the /dev/disk/by-uuid/, and <uuid1>, <uuid2>, and <uuid3> are not listed in the directory.

I noticed that there are some information related to /dev/sdc in the bootup messages:

Code:

md/raid0:md127: looking at sdc
md/raid0:md127:   comparing sdc(3907024128) with sdc(3907024128)
md/raid0:md127:   END
md/raid0:md127:   ==> UNIQUE
md/raid0:md127: 1 zones
md/raid0:md127: looking at sdd
md/raid0:md127:   comparing sdd(3907024128) with sdc(3907024128)
md/raid0:md127:   EQUAL
md/raid0:md127: FINAL 1 zones
md/raid0:md127: done.
md/raid0:md127: md_size is 7814047744 sectors.
******* md127 configuration *********
md127: detected capacity change from 0 to 4000792444928
 md127: unknown partition table

It seems that my raid is md127. I used mdadm to check /dev/md127

Code:

$ mdadm -vv --detail /dev/md127
/dev/md127:
      Container : /dev/md0, member 0
     Raid Level : raid0
     Array Size : 3907023872 (3726.03 GiB 4000.79 GB)
   Raid Devices : 2
  Total Devices : 2

          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

     Chunk Size : 128K

           UUID : fafd6ca4:531b03c4:c26b0653:3f5f5c85
    Number   Major   Minor   RaidDevice State
       1       8       32        0      active sync   /dev/sdc
       0       8       48        1      active sync   /dev/sdd

The UUID displayed above is neither <uuid1>, <uuid2>, nor <uuid3>.

Does anyone know how to solve this problem? Thanks a lot.