On Sat, Apr 21, 2001 at 06:52:01PM +0300, Ville Holma wrote:
...
>
> debian:~# e2fsck /dev/hdb7
> e2fsck 1.18, 11-Nov-1999 for EXT2 FS 0.5b, 95/08/09
> Corruption found in superblock. (frags_per_group = 2147516416).
>
> 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 -2147450879 <device>
>
>
> So I tried to use the huge block size like e2fsck suggests and I get this
>
>
> debian:~# e2fsck -b -2147450879 /dev/hdb7
> e2fsck 1.18, 11-Nov-1999 for EXT2 FS 0.5b, 95/08/09
> e2fsck: Attempt to read block from filesystem resulted in short read while
> trying to open /dev/hdb7
> Could this be a zero-length partition?
>
>
> This is where the human panic occured. There is data on that partition that
> I _really_ do not want to loose. I'm clueless and woud appreciate any
> help/suggestions. If some additonal information is needed I'm more than
> happy to deliver.
I run in similar trouble last week after a power breakage.
My superblock was also corupted and I got also the message to try an other
superbock, but I don't know at which address it was (e2fsck don't show you
the correct addresses, it gives only a syntax example). Remembering that
mke2fs shows it, I use it with the test option "-n" (so it only simulate
the making of a filesystem) and got the addresses for the spare superblocks
and was able to recover the filesystem with no data lost.
example:
pingi:~ # mke2fs -n /dev/sdb3
mke2fs 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
91392 inodes, 182739 blocks
9136 blocks (5.00%) reserved for the super user
First data block=0
6 block groups
32768 blocks per group, 32768 fragments per group
15232 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840
Don't miss the -n option !!!
e2fsck -b 32768 /dev/sdb3
Here are also some howtos related to restoring data and undelete files.
-- Karsten Keil SuSE Labs ISDN development - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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