[libvirt-users] libvirtError: this function is not supported by the connection driver: virDomainSnapshotNum

I tried to create && open a snapshot of xen and the error appears. Is there anyway to support xen snapshotting with libxl/libvirt? This blog http://searchservervirtualization.techtarget.com/tip/Creating-snapshots-in-X... offers two way to backup xen vm with linux commands, can we integrate it into libvirt?