Software RAID doubt

Linux and Unix-Like Red Hat
1

hi friends,
I am having issues with adding a spare device to a failed array.

I have created RAID 1 with 3 partitions using mdadm command. Later I added a spare with

mdadm --add /dev/md0 /dev/sdb6

This works fine and when I check this with mdadm --detail command it just sits there as a spare device.
And now, if I set one of the active raid device in the array as faulty, the spare device becomes active and the failed device becomes faulty spare. This looks perfect, but once i reboot the machine and type mdadm --detail /dev/md0, both the failed device as well as the spare device are not seen in the array..

Why is this happening...where am i going wrong..?

pls help

2

what does your mdadm.conf file look like?

what about /proc/mdstat?

3

hi mark, i dont have an mdadm.conf file...(This is RHEL 5 system). I could not locate where this file is...sorry.

4

What is the ouput from mdadm --detail?

You should have an /etc/mdadm.conf configuration file. If you do not have one, you need to create one.

5

Initial stage of the raid array:

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       3       13        2      active sync   /dev/hda13

       3      3        14       -       spare   /dev/hda14

after the mdadm --fail /dev/hda13

    Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       3       14       2      active sync   /dev/hda14

      3      3        13      -       faulty spare     /dev/hda13

after rebooting..
both the faulty spare (/dev/hda13) and the newly active raid device (/dev/hda14) are removed from the array... and only /dev/hda11 and /dev/hda12 are active.
I touched a file named /etc/mdadm.conf, but nothing is configured there nor any output from that file..

6

do this:

mdadm --examine --scan > /etc/mdadm.conf

---------- Post updated at 12:58 AM ---------- Previous update was at 12:56 AM ----------

[quote=
i touched a file named /etc/mdadm.conf, but nothing is configured there nor any output from that file..[/quote]

It is a conf file, not a log, so you won't get output. This is probably why you are having your issues. I have given the command on how to create this file.

7

hi mark,
thanks. I will do as u guided and let u know the results.bye.

---------- Post updated 08-04-09 at 10:19 PM ---------- Previous update was 08-03-09 at 11:08 PM ----------

mark, I have tried as you mentioned, but i am not successful. The same things happen after I set one of the active device as faulty, (both the faulty device as well as the spare device gets removed...).

8

what is the output of the command? How did you build this array? What is the output of cat /proc/mdstat ?