botched RAID, now e2fsck or what?

Lucian Șandor lucisandor at gmail.com
Tue Dec 8 16:48:18 UTC 2009


Hi all,

Somehow I managed to mess with a RAID array containing an ext3 partition.

Parenthesis, if it matters: I disconnected physically a drive while
the array was online. Next thing, I lost the right order of the drives
in the array. While trying to re-create it, I overwrote the raid
superblocks. Luckily, the array was RAID5 degraded, so whenever I
re-created it, it didn't go into sync; thus, everything besides the
RAID superblocks is preserved (or so I think).

Now, I am trying to re-create the array in the proper order. It takes
me countless attempts, through hundreds of permutations. I am doing it
programatically, but I don't think I have the right tool.
Now, after creating the array and mounting it with
mount -t ext3 -n -r /dev/md2 /media/olddepot
I issue an:
e2fsck -n -f /media/olddepot
However, I cycled through all the permutations without apparent
success. I.e., in all combinations it just refused to check it, saying
something about "short read" and, of course, about invalid file
systems.

Does anybody know a better tool to check whether the mounted partition
is a slightly damaged ext3 file system? I am thinking about dumping
ext3 superblocks, but I don't know how that works.

Thanks.

(I am on the latest openSuSE, 11.2, with the latest mdadm available.)




More information about the Ext3-users mailing list