superblock error after power failure ---on an old system

["Wierdl Máté" <wierdlmate@gmail.com>]

Hello,

I have an old Dell Poweredge 2500 server running Fedora Core 3. The
server  had one of its power units failed, and (I think) as a result,
the raid arrays got damaged: three of them stayed alive (though
degraded), but one is not accessible. Unfortunately, the server only
has a floppy drive which doesn't work now, and so I cannot get any
files, command outputs directly off the box.  I copy it all from the
screen.

The array I cannot access is md3. It has the shared libraries on it so
many commands do not work. In particular, I cannot have remote access
to the box.

 The output of

mdadm -Es

is (I am not copying the UUIDs)

ARRAY /dev/md0 level=raid1 num-devices=2 devices=/dev/sdb2,/dev/sdc2
ARRAY /dev/md2 level=raid1 num-devices=2 devices=/dev/sda6,/dev/sdc3
ARRAY /dev/md3 level=raid5 num-devices=3 devices=/dev/sda3,/dev/sdb1,/dev/sdc1
ARRAY /dev/md1 level=raid1 num-devices=2 devices=/dev/sda1,/dev/sda2

Also

md0  mounted at /
md2 mounted at /var
md1  mounted at /boot
md3 should be mounted at /home

# cat /proc/mdstat
Personalities: raid1 raid5
md1: active raid1 sda2[1] sda1[0]
         104320 blocks [2/2] [UU]

md2: active raid1 sda6[0]
         513984 blocks [2/1] [U_]

md0: active raid1 sdc2[1]
        1534080 blocks [2/1] [_U]

unused devices: none

# mdadm --detail /dev/md3
mdadm: md device /dev/md3 does not appear to be active

At somebody's suggestion I tried

mdadm --assemble --scan /dev/md0

and got

/dev/sda has no superblock - assembly aborted

Then tried

mdadm  --force --run /dev/md3

and got

failed to run array /dev/md3: Invalid argument

I finally tried

# mdadm --assemble /dev/md3 /dev/sda3 /dev/sdb1 /dev/sdc1
mdadm: device 1 in  /dev/md3 has wrong state superblock, but /dev/sdb1 seems ok

Thanks for any help. I certainly would give remote access to a helping
hand, but unfortunately the box cannot run sshd: the shared libraries
are on the md3 array.

Máté

Máté Wierdl
Dept of Math Sci, Univ of Memphis
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