[libvirt-users] Snapshots: Where they are stored and how to use them?

[Roland Giesler]

Firstly I'd like to learn where a snapshot is stored once it has been
made.  I understand that the principle is that when changes occur in
the VM, the difference is written to the snapshot, thus recording the
differences between the date/time of the snapshot and the current
value of the VM.  Is that a correct assessment of the process?

If that is indeed so, can I take regular snapshots and back then up
onto external storage to provide a sort of system restore point at
certain times in the past?

I have scanned the server hard disks for the snapshot images after
running "sudo virsh snapshot-create Windows /etc/libvirt/snapshot.xml"
and the system reports a snapshot was taken, yet I cannot find any
file that contains the snapshot.

$ sudo virsh snapshot-list Windows
 Name                 Creation Time             State
------------------------------------------------------------
 Windows              2013-10-02 12:41:06 +0200 running

What will happen to the snapshot if the host server is restarted?

Some insight would be greatly appreciated.

regards

Roland