Software RAID issue in RHEL5

saagar · 07-30-2009, 04:10 PM

hi friends,
I have created RAID 1 containing 3 partitions in the same hard disk.

Code:

#mdadm --create /dev/md0 --level=1 --raid-devices=3 /dev/hda{11,12,13}
#mdadm --detail /dev/md0
Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       0        0        2      active sync   /dev/hda13

Now, I am setting the /dev/hda13 as faulty..

Code:

#mdadm --set-faulty /dev/md0 /dev/hda13
#mdadm --detail /dev/md0

  Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       0        0        2      removed

       3       3       13        -      faulty spare   /dev/hda13

Now, i rebooted the system and when I type
#mdadm --detail /dev/md0, it shows the following:

Code:

Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       0        0        2      removed

The /dev/hda13 partition is automatically removed..
Why is this so..?

Even if I add a new hot spare and reboot the system, only /dev/hda11 and /dev/hda12 could be seen.. the new hot spare is not permamently sitting there in the raid array...
please help..!

vishesh · 07-31-2009, 02:39 AM

Dear sagar

do you creating RAID 1 with three disk ?

saagar · 07-31-2009, 02:40 PM

what is wrong in creating raid 1 with 3 disks...?

by the way, the same error occurs for RAID 5 also.

vishesh · 08-01-2009, 12:59 AM

Try this

#mdadm --create /dev/md0 --level=1 -x 1 --raid-devices=3 /dev/hda{11,12,13}

Thanks

saagar · 08-01-2009, 10:44 AM

vishesh,
thanks for your response. i will try that and respond to you. thanks a lot.

saagar · 08-02-2009, 12:47 AM

hi vishesh,
I tried with the -x option, it accepts the command and works, but..once I fail one of raid array disks, this spare becomes active and the failed one becomes a faulty spare, ...then once i reboot the machine and issue the mdadm --detail /dev/md0 both the faulty spare and the new active device(which we configured as a spare before)are removed.
the same thing happens for raid5.
can u help with this....?
thanks.

vishesh · 08-02-2009, 03:53 AM

Is there any relevant messages in log files.

Thanks

saagar · 08-03-2009, 12:24 PM

vishesh,
I will check out and let u know.