On Sat, May 30, 2015 at 02:35:51AM +0000, Boylan, Ross wrote:

Does libvirt support snapshotting when the virtual disk comes from a vmdk file?

From my quick test (refer below), seems like you can at-least use VMDK as a backing file.

http://wiki.libvirt.org/page/Snapshots#Desired_functionality seems to say no, since it says "'virsh snapshot', which requires all disk images to be qcow2".

OTOH, man virsh, http://libvirt.org/formatsnapshot.html, and http://libvirt.org/formatdomain.html#elementsDisks seem to indicate more flexibility, though I see nothing about vmdk.

If there is support for vmdk, is it just for external snapshots, or do internal snapshots work?

From my quick test (for offline disks with `qemu-img`), it does seem to work:

$ qemu-img create -f vmdk base.vmdk 1G $ qemu-img create -f qcow2 -o \ 'backing_file=./base.vmdk,backing_fmt=vmdk' ./overlay1.qcow2 $ qemu-img info overlay1.qcow2 image: overlay1.qcow2 file format: qcow2 virtual size: 1.0G (1073741824 bytes) disk size: 196K cluster_size: 65536 backing file: ./base.vmdk backing file format: vmdk Format specific information: compat: 1.1 lazy refcounts: false And, as near as I know, internal snapshots are a feature of qcow2 format.

Currently running libvirt 0.9.12, qemu-kvm 1.1.2 (though I could use vmware workstation), linux kernel 3.2.0.

-- /kashyap