Topic: DegradedArray event Assistance Please

[Mjohnson]

Receivd the following email message:

This is an automatically generated mail message from mdadm
running on server

A DegradedArray event had been detected on md device /dev/md2.

Output for the command

mdadm --query --detail /dev/md[12]

was:

/dev/md1:
        Version : 00.90.01
  Creation Time : Tue Aug  1 15:08:30 2006
     Raid Level : raid1
     Array Size : 104320 (101.88 MiB 106.82 MB)
    Device Size : 104320 (101.88 MiB 106.82 MB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Fri Sep 22 22:13:48 2006
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0


    Number   Major   Minor   RaidDevice State
       0       3        1        0      active sync   /dev/hda1
       1       3       65        1      active sync   /dev/hdb1
           UUID : 3bfddc38:78c98168:51016b85:bdeaa0a7
         Events : 0.555
/dev/md2:
        Version : 00.90.01
  Creation Time : Tue Aug  1 15:07:11 2006
     Raid Level : raid1
     Array Size : 117113728 (111.69 GiB 119.92 GB)
    Device Size : 117113728 (111.69 GiB 119.92 GB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Fri Sep 22 22:57:43 2006
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0


    Number   Major   Minor   RaidDevice State
       0       0        0       -1      removed
       1       3       66        1      active sync   /dev/hdb2
           UUID : 324652ca:19f16aaf:6d3b5367:b6ad6dda
         Events : 0.816152

What I am confused about is that md1 appears to be OK, but md2 appears to have failed.  They are differnt partitions on the same drive, correct?
Do I replace the drive?  

Many thanks.

[ldkeen]

First of all from what I can see you have both your raid devices hanging of the same channel, which is not a very good thing. It is recommended that your disk drives be set as the primary device on seperate channels (/dev/hda and /dev/hdc). Looking at your problem, I don't think the drive has failed because /dev/hda1 is still a member of /dev/md1. For some reason /dev/hda2 has gone MIA from /dev/md2. The output actually says that it has been removed.

Number Major Minor RaidDevice State
0 0 0 -1 removed
1 3 66 1 active sync /dev/hdb2
UUID : 324652ca:19f16aaf:6d3b5367:b6ad6dda
Events : 0.816152

Maybe the array is rebuilding itself after a dirty shutdown?? Have a look at:

Code: [Select]

#cat /proc/mdstat
to see if it is reconstructing. If not try hot adding the drive back into the array:

Code: [Select]

#mdadm -a /dev/md2 /dev/hda2
Lloyd

[william_syd]

Code: [Select]

#cat /proc/mdstat
to see if it is reconstructing.
Lloyd

I like this one...

Code: [Select]

watch -n .1 cat /proc/mdstat

[Mjohnson]

Gentlemen,

Thank you for your very helpful replies.

The mirror is recovering now.  I am curious as to what went askew here.  I will take another look under the hood and see if anything jumps out at me.

MJ