[libvirt] Re: [RFC] Live disk snapshot API

Disk snapshot API needs to be general and flexible enough to support various storage and snapshot methods. Examples of what can be used for creating disk snapshots are: QEMU qcow2 snapshots, LVM snapshots, filesystems with snapshot support (btrfs, zfs, ...), enterprise storage. Moreover, method used to create disk snapshot does not have to be determined by disk type. One can have a qcow2 disk stored on btrfs inside lvm logical volume; snapshot of such disk can be done at any of the three levels.