[libvirt] libvirt external snapshot error

Hi, i'm using virsh -c qemu+ssh://test.node/system snapshot-create-as 40083 --no-metadata --disk-only --live –atomic --diskspec sda,file=/test outputs: error: Operation not supported: live snapshot creation is supported only with external checkpoints info: Compiled against library: libvirt 1.2.16 Using library: libvirt 1.2.16 Using API: QEMU 1.2.16 Running hypervisor: QEMU 2.4.1 Does it supported on never libvirt? How can i solve the issue? I'm use raw format for disk. -- Vasiliy Tolstov, e-mail: v.tolstov(a)selfip.ru