Ext3 users - Nov 2011 - damaged encrypted LUKS device

Hi people,

i had created encrypted device with cryptsetup/LUKS which i setup with 
an ext4 filesystem. This device is an external USB harddisk. When i 
plugin this device it will be automatically mounted by my gnome3 system 
(Debian Wheezey/Testing), but this week i got an error. I did ask the 
ask the LUKS developers what is the problem and they told me that this 
is an ext4 problem.

The error message from gnome is:
> Einh?ngen von AIRY_1TB nicht m?glich
>
> Error mounting: mount: wrong fs type, bad option, bad superblock on
/dev/mapper/udisks-luks-uuid-70a2aedf-ce7e-4e12-8f0b-ec7974ebdbd4-uid1000,
> missing codepage or helper program, or other error
> In some cases useful info is found in syslog - try
> dmesg | tail or so



And from <dmesg> i got the message:
> [ 3094.394043] EXT4-fs (dm-0): ext4_check_descriptors: Inode bitmap for
group 3328 not in group (block 1235654634)!
> [ 3094.394056] EXT4-fs (dm-0): group descriptors corrupted!
Further on, when i try to <fsck -N /dev/sdb> i
get:
> fsck from util-linux 2.19.1
> fsck: fsck.crypto_LUKS: not found
> fsck: Error 2 while executing fsck.crypto_LUKS for /dev/sdb
But cryptsetup is installed, only lvm2 is missing, but i dont have a LVM 
device and as i researched at "debian.org" there is no package which 
provides the command <fsck.crypto_LUKS>.


Any hints/instructions for me?

regards Markus

On Sat, Nov 26, 2011 at 03:15:42PM +0100, Markus Feldmann
wrote:
> And from <dmesg> i got the message:
> >[ 3094.394043] EXT4-fs (dm-0): ext4_check_descriptors: Inode bitmap for
group 3328 not in group (block 1235654634)!
> >[ 3094.394056] EXT4-fs (dm-0): group descriptors corrupted!
> 
> Further on, when i try to <fsck -N /dev/sdb> i get:
> >fsck from util-linux 2.19.1
> >fsck: fsck.crypto_LUKS: not found
> >fsck: Error 2 while executing fsck.crypto_LUKS for /dev/sdb
> 
> But cryptsetup is installed, only lvm2 is missing, but i dont have a
> LVM device and as i researched at "debian.org" there is no
package
> which provides the command <fsck.crypto_LUKS>.
> 
> Any hints/instructions for me?
try "e2fsck -C0 /dev/dm-0" (assuming /dev/dm-0 is your block device 
after decryption).

And do full block-by-block backup of your external USB disk first! 
(using dd(1))

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