very weird uuid problem with vol_id and /dev/disk/by-uuid/

[Knapp]

Read the thread, last 2 messages are the key.
Re: I still need help!! Re: Can't play DVD SOLVED!

Just to see if it is a quick fix, try renaming
/etc/udev/rules.d/70-persistent-cd.rules
to
/etc/udev/rules.d/70-persistent-cd.Backup
and reboot.
I bet in your case it does not work because we are not talking cd or
dvd but might be worth a try or something along the same lines.

On Wed, Jun 3, 2009 at 9:41 PM, Dolf Andringa <dolf.andringa at elcyon.nl> wrote:
> hey people.
>
> I have a very weird problem in an Ubuntu Hardy machine running inside a
> Xen virtual machine.
>
> I have /dev/sdb1 setup with LVM. After a reboot this didn't come back up
> and the problem seems to be related to a uuid problem (physical volume's
> uuid is wrong, causing lvm not to find the volume group).
>
> Somehow "vol_id /dev/sdb" returns "47caf26c-7491-4b24-a5cc-cd7825518ef3"
> as the vol_id, but "vol_id /dev/sdb1" says "Unkown volume type". This is
> weird, since normally, only the partitions should return a vol_id, not
> the block device.
> When  I run "fdisk -l" I do see the correct partition table though:
>
> Disk /dev/sdb: 4294 MB, 4294967296 bytes
> 255 heads, 63 sectors/track, 522 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x58a3ad78
>
>   Device Boot      Start         End      Blocks   Id  System
> /dev/sdb1               1         522     4192933+  8e  Linux LVM
>
>
> When I take a look at /dev/disk/by-uuid/ I see the following:
> lrwxrwxrwx 1 root root 10 2009-06-03 21:21
> 47caf26c-7491-4b24-a5cc-cd7825518ef3 -> ../../sdb1
> lrwxrwxrwx 1 root root 10 2009-06-03 21:21
> 64db3117-17d9-463f-b560-7df7392a5816 -> ../../sda1
> lrwxrwxrwx 1 root root 10 2009-06-03 21:21
> c9e88347-58fd-4c8d-93d8-c0d8228d58eb -> ../../sda2
>
> So there is a link to /dev/sdb1, and /dev/sdb1 seems to contain a uuid,
> but it is the same as what vol_id reports as the uuid for /dev/sdb. It
> really seams the mappings of the devices got mixed up, but I don't know
> how, and how to fix this.
>
> I hope someone can help me out with this.
>
> Cheers,
>
> Dolf.



-- 
Douglas E Knapp

Why do we live?