Is my RAID degraded or not?

ppshay · 29-12-2012 4:58am #1

I have 4 x 2TB Sata drives in a CentOS box for backups.

In Webmin when I go to Hardware > Linux RAID, /dev/md0 and md1 is showing a failed disk but /dev/md2 is not - as per the screenshots.

I don't know a lot about Linux and wondering why this is happening.

Tillotson · 29-12-2012 9:28pm

Looks like one of your disks have failed. You'll need to identify which disk and replace. Hopefully you have labelled your disks :P

You can tell which disk is faulty from the shell:

[root@brain /]# mdadm --detail /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Fri Sep  7 18:51:08 2012
     Raid Level : raid5
     Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
  Used Dev Size : 2930134016 (2794.39 GiB 3000.46 GB)
   Raid Devices : 3
  Total Devices : 3
    Persistence : Superblock is persistent

    Update Time : Sat Dec 29 20:15:46 2012
          State : clean, degraded
 Active Devices : 2
Working Devices : 2
 Failed Devices : 1
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : brain:0  (local to host brain)
           UUID : 3111f917:ed9f2461:e469efed:9b4a1881
         Events : 274

    Number   Major   Minor   RaidDevice State
       4       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       0        0        2      removed

       3       8       33        -      faulty   /dev/sdc1

ppshay · 30-12-2012 11:31pm

Thanks. Any idea why two logical drives show a failure and one (the main data drive) doesn't?

I was getting failures on MD2 on previous occaisions so I removed the drive from the RAID (software) and re-added and rebuilt and it would be ok again for a couple of months. I will get a RAID card and see if that works better.

Is my RAID degraded or not?

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