[libvirt] Proposal for snapshotting functions of volumes

Hi, Currently libvirt is lacking support for snapshotting volumes through the storage pool mechanism. I want to add this to libvirt, but since the internals and the API design ideas of libvirt are not fully known to me I wanted to put this up for a basic review first. This patch can also be viewed on Github: https://github.com/wido/libvirt/commit/4483ab247f607250c5b3314d0a19509ef2... My main questions are: * Is this something we would like to see in libvirt? * If so, am I on the right track? * If so, what API calls should be different? The steps I want to take: 1. Add the new API calls 2. Add support to the RBD backend 3. Add support to virsh 4. Add support to the Java bindings The Apache CloudStack project uses libvirt intensively and I want to add as much support to libvirt as we need so that we don't do stuff inside CloudStack where libvirt might be a lot better place to do it. Any comments are very much appreciated before I start spending hours of my time on this :) Wido