(0) 
$ virsh start cirrvm

(1)
$ virsh domblklist cirrvm
Target     Source
------------------------------------------------
hda        /export/images/sn2.sn1

(2) 
$ virsh dumpxml --inactive cirrvm > /var/tmp/cirrvm.xml

(3) 
$ virsh undefine cirrvm
Domain cirrvm has been undefined

(4)
$ virsh domblklist cirrvm
Target     Source
------------------------------------------------
hda        /export/images/sn2.sn1
 
(5)
$ virsh blockcopy --domain cirrvm hda /export/images/copy-sn2.sn1.qcow2 --wait --verbose --finish
Block Copy: [100 %]
Successfully copied

(6)
$ virsh define /var/tmp/cirrvm.xml
Domain cirrvm defined from /var/tmp/cirrvm.xml