Re: [dm-crypt] reinstallation

[Moji <lordmoji@gmail.com>]

I do not entirely understand your question, so I apologize if my answer
is not what you are looking for.

If you repeated those steps then any information on /dev/sda2 will be
lost forever.

"luksFormat" writes the luks header information, that includes the key
that decrypts the rest of the partition(device). If there is an old key
it will write over it making any old data on that luks partition
effectively unrecoverable.

"luksOpen" uses your supplied key to decrypt the device key stored in
the header information and then maps it to /dev/mapper/.

If I understand your original post, the "/dev/sda2" is currently
unencrypted data? If that is the case then you MUST copy that data over
to another device while you set up then encrypted partition, then
transfer it back, as the steps you listed will erase your old partition.

-MJ

RaMaier@gmx.de wrote:
> Hi Hannes,
> in the documents I keep. I found that I had encrypted /dev/sda2. The procedure I recorded was:
> umount /dev/sda2
> cryptsetup luksFormat /dev/sda2
> cryptsetup luksOpen /dev/sda2 tresor
> mkfs.ext3 /dev/mapper/tresor
> mount /dev/mapper/tresor /tresor
> 
> What will happen if I repeat the steps ?
> Should I just leave the mkfs.ext3 out ?
> Would I be able to access my old data again ?
> What does lufsFormat really do ? Format the partition ?
> As I staded the data is pretty valuable to me.
> 
> thanks for your help.
> Best regards
> Rainer
> 
> 
> -------- Original-Nachricht --------
>> Datum: Tue, 11 Aug 2009 16:01:56 +0200
>> Von: Hannes Erven <h.e@gmx.at>
>> An: Rainer Maier <RaMaier@gmx.de>
>> CC: dm-crypt@saout.de
>> Betreff: Re: [dm-crypt] reinstallation
> 
>> Hi Rainer,
>>
>>
>>> How can I reinstall LUKS on my new Debian (Lenny)?
>> I guess the debian (and thus cryptsetup) installations on your old
>> machine weren't that up to date, right?
>>
>> With the new debian lenny, you don't need to install anything: LUKS is
>> already included in the default cryptsetup package you should already
>> have installed (http://packages.debian.org/lenny/cryptsetup ).
>>
>>> >From http://code.google.com/p/cryptsetup/:
>> "The former version of cryptsetup only had low-level operations for
>> dm-crypt ready, and around version cryptsetup-luks 1.0.5 was renamed to
>> be the official version of cryptsetup. "
>>
>> You still might have to change your old scripts, if you have some, to
>> just call cryptsetup instead of cryptsetup-luks .
>>
>>
>> HTH, best regards
>>
>> 	-hannes
>>
>>
>>
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>