Can you post the output of tune2fs for that partition?
a# tune2fs -l /dev/hda8
tune2fs 1.41.3 (12-Oct-2008)
Filesystem volume name: <none>
Last mounted on: <not available>
Filesystem UUID: c95da523-5d03-40be-bdfa-28f6540ee9ba
*Filesystem magic number: 0xEF53*
Filesystem revision #: 1 (dynamic)
Filesystem features: ext_attr resize_inode dir_index sparse_super
large_file
Filesystem flags: signed_directory_hash
Default mount options: (none)
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Hurd
Inode count: 794624
Block count: 3176845
Reserved block count: 158842
Free blocks: 3113535
Free inodes: 789880
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 775
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8192
Inode blocks per group: 256
Filesystem created: Tue Apr 14 14:28:55 2009
Last mount time: Mon Apr 20 16:09:29 2009
Last write time: Mon Apr 20 16:12:03 2009
Mount count: 21
Maximum mount count: 26
Last checked: Tue Apr 14 22:42:01 2009
Check interval: 15552000 (6 months)
Next check after: Sun Oct 11 22:42:01 2009
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 128
Default directory hash: half_md4
Directory Hash Seed: 60202b85-b61d-4fd0-a806-78ce2f9362c1
The strange think is that the magic number is effectively 0xef53 and not
0x8b17 like the error say...
