[pkg-cryptsetup-devel] Bug#585934: [udev] UUID discrepancy between cryptsetup luksUUID and udevadm info

[Milan Broz]

On 06/16/2010 12:01 AM, Marco d'Itri wrote:
> On Jun 15, Guy Heatley <guy.encrypt at member.fsf.org> wrote:
> 
>> r2d2:/home/guy# blkid -o udev /dev/sdc1
>> ID_FS_LABEL=/
>> ID_FS_LABEL_ENC=\x2f
>> ID_FS_UUID=5e6cf0a2-ac35-4d8b-b1cf-f75ad8427551
>> ID_FS_UUID_ENC=5e6cf0a2-ac35-4d8b-b1cf-f75ad8427551
>> ID_FS_SEC_TYPE=ext2
>> ID_FS_TYPE=ext3
> And did udev create links to sdc1 in /dev/disk/ this time?
> 
>> r2d2:/home/guy# cryptsetup luksUUID /dev/sdc1
>> bf6cfa88-8f0c-4e07-ae24-84b25e7e7960
>>
>> Hmmm... contradictory

Nope. You are mixing up two UUIDs:

luksUUID is the UUID from LUKS header of underlying device (/dev/sdc1),

ID_FS_UUID is UUID of fs on top of it (here labeled "/", it is device /dev/mapper/sdc1_crypt or so).

(You can use luksUUID even if device is not active, but FS UUID and label is visible only on active LUKS device.)

Milan