ext3 corrupted

[Lennart Sorensen]

On Sat, Jul 21, 2007 at 05:37:19PM -0400, Marc Lijour wrote:
> I have a drive that got corrupted (just before it started to send SMART 
> alerts). I can't mount it and I get this error message:
> 
> EXT3-fs error (device sda12): ext3_check_descriptors: Block bitmap for group 
> 896 not in group (block 16777317)!
> 
> I can't mount it as ext2 either, and I can't mount sda either. auto as type 
> does not work either.
> 
> Running fsck and accepting all actions with a 'y' seems to have no effect. I 
> can't mount the disk and when I get to do fsck again I get the same actions.
> 
> dd works.
> 
> Do you know a way to get the data back?
> 
> Thanks a lot (!)

Well you could try fsck with the -b 8193 option to tell it to use an
alternate superblock.  Might work.

If the drive is actually going bad, certainly the advice of letting it
cool off is a good one.  I actually managed to recover all the data from
a failed drive for my sister that refused to even try to boot, by trying
it out right after getting home in the middle of winter while the
computer was probably at about -10C.  Read everything perfectly and got
all the data of it and onto new dists (I replaced it with raid1).
Didn't even get a single read error, it just ran perfectly.  I have read
that a lot of recovery people will actually freeze the drive before
trying to read it since it apparently works quite well in many cases
without having to do anything complicated.

--
Len Sorensen
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