From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <uwe.menges@web.de>
Received: from h604816.serverkompetenz.net (h604816.serverkompetenz.net
	[81.169.142.96]) by mail.saout.de (Postfix) with ESMTP
	for <dm-crypt@saout.de>; Thu, 10 Dec 2009 02:20:37 +0100 (CET)
Message-ID: <4B204CE4.3080104@web.de>
Date: Thu, 10 Dec 2009 02:20:36 +0100
From: Uwe Menges <uwe.menges@web.de>
MIME-Version: 1.0
References: <6F8A7585-60EB-4844-90B9-06EE3BB2A76E@thompsonlogic.com>
In-Reply-To: <6F8A7585-60EB-4844-90B9-06EE3BB2A76E@thompsonlogic.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [dm-crypt] how to determine the mapped device from the original
 device
List-Id: <dm-crypt.saout.de>
List-Unsubscribe: <http://www.saout.de/mailman/options/dm-crypt>,
	<mailto:dm-crypt-request@saout.de?subject=unsubscribe>
List-Archive: <http://www.saout.de/pipermail/dm-crypt>
List-Post: <mailto:dm-crypt@saout.de>
List-Help: <mailto:dm-crypt-request@saout.de?subject=help>
List-Subscribe: <http://www.saout.de/mailman/listinfo/dm-crypt>,
	<mailto:dm-crypt-request@saout.de?subject=subscribe>
To: dm-crypt@saout.de

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)?

I don't know that, but I use entries in /etc/crypttab like:

backup01 /dev/disk/by-uuid/... /dev/shm/backupkey luks,noauto

and use

# cryptdisks_start backup01

which causes /dev/mapper/backup01 to appear.
Corresponding /etc/fstab entry is:

LABEL=backup01  /backup/disk1 auto noauto,noatime,nodiratime

Maybe this helps you with handling the devices.

Yours, Uwe