Re: [dm-crypt] how to determine the mapped device from the original device

[Milan Broz <mbroz@redhat.com>]

On 12/10/2009 01:37 AM, Alvin Thompson wrote:
> I was wondering if it is possible to determine the mapped device from the original device.  For example, if you used the command:
> 
>   cryptsetup luksOpen /dev/sdd1 backup
> 
> Can you later determine the mapped device name ('backup' in this case) if all you know is the device (/dev/sdd1)?

For really low-level, you can try dmsetup.

If you know the major:minor of that device (ls -l /dev/sdd1) check "dmsetup ls --tree" or similar.
The reverse is "cryptsetup status backup" and see device there.

All active encrypted devices you can see with "dmsetup status --target crypt" (or dmsetup table and check table directly).

Anyway, this seems like good idea to add some new command to cryptsetup, like "cryptsetup deps <dev>" to display
encrypted device mapped to underlying <dev>... add new issue to project page if you want this please.

Milan
--
mbroz@redhat.ocm