[linux-lvm] /dev/dm-0 instead of /dev/mapper/mygroup-myvol in "mount" output

[Benjamin Henrion]

On Fri, Jul 9, 2010 at 9:53 AM, Benjamin Henrion <bh at udev.org> wrote:
> Hi,
>
> I have managed to setup an LVM loopback file as a harddisk to mount.
>
> Now, I need the vzdump utility to detect the fact that it is LVM
> based, and it keeps saying that it cannot detect the LVM volume group:
>
> http://openvz.org/pipermail/users/2010-July/003623.html
>
> "unable to detect lvm volume group"
>
> Everything works fine when mount displays that the file is mounted
> with /dev/mapper/mygroup-myvol, on the opposite, it does not work when
> mount outputs /dev/dm-0 in its list.
>
> Any idea how I could force mount to use /dev/mapper/mygroup-myvol
> instead of /dev/dm-0?

On one machine it creates rightly a device on /dev/mapper:

root at buzek /dev/mapper [68]# l
total 0
crw-rw---- 1 root root  10, 59 2010-07-09 09:32 control
brw-rw---- 1 root disk 254,  0 2010-07-09 10:44 openvzgroup-openvzvol

While on the other machine where is does not work, it makes a symlink
to /dev/dm-0:

root at chainsaw /dev/mapper [25]# l
total 0
crw-rw---- 1 root root 10, 59 2010-07-09 10:28 control
lrwxrwxrwx 1 root root      7 2010-07-09 10:46 openvzgroup-openvzvol -> ../dm-0

Any idea why this difference?

-- 
Benjamin Henrion <bhenrion at ffii.org>
FFII Brussels - +32-484-566109 - +32-2-4148403
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