[CentOS-virt] About doing backups with kvm guests

Sat Dec 12 20:39:03 UTC 2009
Christopher G. Stach II <cgs at ldsys.net>

----- "Kenni Lund" <kenni at kelu.dk> wrote:

> I'm also very interested in how to make backups of Windows guests on
> LVM. But will the shadow copy feature in amanda not only backup the
> files within the Windows machine? I don't think I fully understand
> the
> method - How do you then do a full restore, eg. with no working
> Windows machine? Would you then have to do a clean install of Windows
> in order to get the partition and bootloader setup correctly, after
> which you can do the restore by overwriting all files?

You can just shut down the VM, make a snapshot, start the VM, dd the snapshot, and finally drop the snapshot.

Or, if that's too much downtime, you can xm save, snapshot, copy save dumpfile, xm restore, dd snapshot, backup dumpfile, and clean up.

If that's too much downtime, you can xm pause, snapshot, xm unpause, etc., but you will have issues with your restore because it will look like the VM crashed and you may or may not lose data.

Personally, I only back up data and never have useful data on a Windows installation volume (or even a native Windows volume, if I can help it). I can reimage a Windows machine with a single command and it only takes a few minutes. (Hint: use Sysprep.) Besides, reinstalling Windows machines is better than restoring them since they progressively bit rot.

Christopher G. Stach II