LVM snapshot not mountable

[Christoph Hellwig]

On Tue, May 25, 2010 at 05:25:44PM +0200, Michael Monnerie wrote:
> This might be LVM specific, please apologize. For the first time I play 
> around with LVM snapshots. I tried this:
> lvcreate -s -n dbsnap -L 4G -v /dev/db/mysql
> mount /dev/db/dbnap /mnt
> but the mount fails, dmesg says:
> [  598.440324] XFS: Filesystem dm-1 has duplicate UUID - can't mount
> 
> How could I mount it?

mount -o ro,norecovery,nouuid /dev/db/dbnap /mnt

or use

 xfs_admin -U generate /dev/db/dbnap

to give it a different uuid first in case you're dealing with a
writeable snapshot.