[ovirt-devel] Re: cloning LVM partitions

On Mon, Jun 28, 2021 at 11:07 AM Laurent Duparchy <duparchy(a)esrf.fr&gt; wrote: We don't use LVM snapshots for VM disks. oVirt snapshots are using qcow2 logical volumes per VM snapshots. For example VM can start with one logical volume: /dev/vgname/lv-1 When you create a snapshot in engine, ovirt creates new logical volume: /dev/vgname/lv-2 And creates a qcow2 image using /dev/vgname/lv-1 as the backing file: /dev/vgname/lv-1 <- /dev/vgname/lv-2 (top) The best way with oVirt 4.4 is to use incremental backup, but you are likely using 4.3. There are several backup solutions that use snapshots to create incremental backup. This is more complex and less efficient but it should be available for your version. Keeping things simple backup at the storage side at the LUN level is probably the simplest way. It may also be the most efficient way depending on the storage capabilities, for example if your storage supports thin provisioning. But note that backup in storage level can create inconsistent backup, so starting a VM after restore may require running fsck. Using snapshots or incremental backup should generally avoid this issue if the VMs have qemu-guest-agent. Nir