Re: automatic mounting of an encrypted harddrive

[Tobias Schula <tobias@schula.org>]

Am Samstag 07 November 2009 17:20:44 schrieb Florian Kulzer:
> On Sat, Nov 07, 2009 at 15:54:17 +0100, Tobias Schula wrote:
> > Am Freitag 06 November 2009 23:21:57 schrieb Florian Kulzer:
> > > On Fri, Nov 06, 2009 at 16:37:11 +0100, Tobias Schula wrote:
> > > > Am Sonntag 25 Oktober 2009 10:28:34 schrieb Florian Kulzer:
> > >
> > > [...]
> > >
> > > > > That probably means that HAL does not set the crypto-related
> > > > > properties for the device, which would explain why KDE does not
> > > > > know how to handle it.
> 
> [...]
> 
> > > These three lines should look like this:
> > >
> > >   volume.fstype = 'crypto_LUKS'  (string)
> > >   volume.fsusage = 'crypto'  (string)
> > >   volume.fsversion = '256'  (string)
> > >
> > > Udev should set these properties based on the results of running
> > > /sbin/blkid on the device, triggered by 60-persistent-storage.rules. We
> > > have to find out why this does not happen on your system.
> > >
> > > Please run
> > >
> > >   udevadm test $(udevadm info --query=path -n /dev/sdc1)
> 
> [...]
> 
> > OK, here's the output: http://debian.pastebin.com/m2a365e1f
> 
> Here is your problem:
> 
>   udev_rules_apply_to_event: IMPORT '/sbin/blkid -o udev -p /dev/sdc1'
>  /lib/udev/rules.d/60-persistent-storage.rules:129 util_run_program:
>  '/sbin/blkid -o udev -p /dev/sdc1' started
>   util_run_program: '/sbin/blkid' (stderr) '/dev/sdc1: ambivalent result
>  (probably more filesystems on the device)' util_run_program: '/sbin/blkid
>  -o udev -p /dev/sdc1' returned with exitcode 2
> 
> Blkid cannot identify the filesystem on sdc1. It should work like this
> (my encrypted USB stick is /dev/sda1):
> 
>   $ /sbin/blkid -p /dev/sda1
>   /dev/sda1: UUID="60160a54-2d59-46f7-b46f-3490a767e820" VERSION="256"
>  TYPE="crypto_LUKS" USAGE="crypto"

Ah, I see, this is the output on my computer:
	# /sbin/blkid -p /dev/sdc1
	/dev/sdc1: ambivalent result (probably more filesystems on the device)


> 
> Make sure you have the up-to-date versions of these packages:
> 
>   $ dpkg -l util-linux libblkid1 libuuid1 | awk '/^ii/{print $2,$3}'
>   libblkid1 2.16.1-4
>   libuuid1 2.16.1-4
>   util-linux 2.16.1-4

All up to date:
	# dpkg -l util-linux libblkid1 libuuid1 | awk '/^ii/{print $2,$3}'
	libblkid1 2.16.1-4
	libuuid1 2.16.1-4
	util-linux 2.16.1-4

> 
> Also, are you sure that you have a standard crypto_LUKS partition? How
> did you set it up?
> 

I erased all data it previously contained:
# dd if=/dev/urandom of=/dev/sdc1

I set up the crypt device:
# cryptsetup luksFormat /dev/sdc1

Opening the device mapper:
# cryptsetup luksOpen /dev/sdc1 crypt_backup

Formating it with ext3:
# mkfs.ext3 /dev/mapper/crypt_backup

Mounting the file system:
# mount /dev/mapper/crypt_backup /mnt

Setting rights:
# chown 1000:1000 /mnt

Unmounting the file system:
# umount /dev/mapper/crypt_backup

Closing device mapper:
# cryptsetup luksClose crypt_backup

After these steps I was able to plug it in and the KDE device notifier showed 
me the new drive. But I didn't set it up in Debian but in Kubuntu if that's 
important.


Regards

Tobias