Hi Sven,
a quick correction: blkid is (surprisingly) not smart enough, and your
command line results in duplicates. Both the /dev (e.g. /dev/sdg) and
the equivalent /dev/disk/by-uuid are listed.
So you want to use:
blkid -t TYPE="crypto_LUKS" -s UUID /dev/disk/by-uuid/*
(tested on Ubuntu 10.04 Lucid).
Thanks,
Yaron
On 12/20/2012 01:00 PM, dm-crypt-request@xxxxxxxx wrote:
Date: Thu, 20 Dec 2012 00:30:23 +0100
From: "Sven Eschenberg" <sven@xxxxxxxxxxxxxxxxxxxxx>
To: dm-crypt@xxxxxxxx
Subject: Re: UUID question
Message-ID:
<18e39b1120b315e7553bdb330e5103c5.squirrel@xxxxxxxxxxxxxxxxx>
Content-Type: text/plain;charset=utf-8
cryptsetup luksUUID <dev> will return the luks header's UUID if <dev>
holds a luks header, and yes, this should usually not change the same way
as the UUID of a filesystem souldn't.
There's 2 problems though:
1.) You'd have to know <dev> in advance or iterate over all possible (non
locked) blockdevices (which is what blkid usually does anyway for you)
2.) a blockdev could possibly hold a luks header and still be part of a md
device (depending on metadata version), you'd better hope that the md
device is set up already, when you issue your cryptsetup commands.
Concerning the original question:
The UUID within the LUKS header should not change throughout the LUKS
volume's lifetime, except for enforced changes (as noted before).
To associated keys based on luks UUID, using something like:
'blkid -t TYPE="crypto_LUKS" -s UUID'
is probably a good starting point, as it gives you the UUID to retrieve
the keys based on the UUID and the device inode you'd use on further calls
to cryptsetup etc. - The rest is just a little shell magic ;-)
Regards
-Sven
_______________________________________________
dm-crypt mailing list
dm-crypt@xxxxxxxx
http://www.saout.de/mailman/listinfo/dm-crypt
