[linux-lvm] File-system uuid on LVM snapshot

[Zdenek Kabelac]

Dne 5.6.2014 10:26, Rajesh Joseph napsal(a):
> Hi all,
>
> Origin volume and snapshot volume share the same file-system UUID. So after the snapshot we fix the uuid by running xfs_admin or tune2fs.
> Do you have any recommendation or best practice in this regard?
>


With thin pools and thin volumes - snapshot of thin volume is now created 
'inactive' and it's skipped from default activation  (you could always 
override skip with -K  i.e. : lvchange -ay -K vg/mythinsnap)

So with thins you should mostly have only a single volume active with the FS 
UUID.  If you happen to have multiple volumes active and you need to mount xfs 
filesystem  - use  'nouuid' (and eventually  norecovery for read-only 
activated snapshots)  mount options.

For old-snapshosts - all volumes need to be available/active - so you need to 
use 'nouuid' option always.

I don't see much point in changing  FS UUID on your snapshot - unless of 
course you plan to use snapshots as different volumes with just a 'single' 
starting point  (i.e. preinstalled tree of files)

Regards

Zdenek