I have a libvirt to control qemu domains with various flavours of Windows on Ubuntu 14.04 Trusty.

The disk images are ZFS volumes.

After I have resolved scheduling problems related to kernel (latest 3.15.3-031503-lowlatency kernel seems to have resolved scheduling and BSOD issues), I have never seen Windows to run this fast, even on bare iron. This is a WONDERFUL combination.

Now I am starting to move forward, and have discovered that snapshot is only supported as QEMU native "savevm" command, which only works on QCOW2 backing image.

Is there any chance to include support for ZFS native snapshots? I.e. do a coordinated RAM snapshot in a separate file, snapshot ZFS volume and tie these two together in a snapshot XML file.

A related, but different question: any chance to support ZFS-backed storage pools, so that ZFS volumes could be created, and not QCOW images in ZFS file system (this is a waste of ZFS, as ZFS already has native COW, snapshots, cloning, migration and much more). Should I start a separate thread for this topic?