On 02/21/2013 01:08 PM, Stone wrote:

ok i have checked all superblocks but i get always the same message.
here one sample:
fsck.ext4 -n -b 644972544 /dev/mapper/md2_nas
e2fsck 1.41.14 (22-Dec-2010)
fsck.ext4: Invalid argument while trying to open /dev/mapper/md2_nas

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 <device>

You very likely have the wrong chunk size.

Close luks, stop md2, and re-create with --chunk=64

And then try to fsck again.  (Without -b at first.)

Phil