[Pkg-cryptsetup-devel] Bug#432150: [dm-crypt] Re: LUKS partitons disappeared

[Jonas Meurer]

On 11/01/2008 Robert Kelly wrote:
> By grepping through a hexdump of the partition, I was able to find that
> there was a LUKS header present. Since it seemed to be near the beginning of
> the partition (short time to find it), I stored a hexdump of the partition
> in a file and used vim to locate the header. From this, I determined that
> the header appeared to be offset 3MB from the beginning of the partition, so
> I used dd to copy it starting from that offset to another partition. This
> was successful and all data was recovered. I am still not certain what is
> responsible for this error, but I thought I would share my experience in
> case it is helpful to someone else.

Hey Robert,

I'm part of the group that maintains cryptsetup in Debian: www.debian.org

Back in July 2007 we got a bugreport which suggests to provide some
'repair tools' for cryptsetup because of several data corruption issues
cryptsetup and/or the linux dm-crypt/device-mapper implementation has.

You can find the relevant bug report at http://bugs.debian.org/432150

Now from what i read in your mails, it seems like you did exactly what
the bug submitter suggested: salve or reconstruct the luks header.

could you elaborate on how exactly you did that, maybe in a way that
could be automated in a script?

i already got that 'hexdump -C -n 1024 /dev/partition' gives information
about the used cipher etc.

thanks in advance,
 jonas