root@server:/etc/mdadm# e2fsck /dev/md0 e2fsck 1.40-WIP (14-Nov-2006) Couldn't find ext2 superblock, trying backup blocks... e2fsck: Bad magic number in super-block while trying to open /dev/md0 The superblock could not be read or does not describe a correct ext2 filesystem. If the device is valid and it really contains an ext2 filesystem (and not swap or ufs or something else), then the superblock is corrupt, and you might try running e2fsck with an alternate superblock: e2fsck -b 8193