Comment 16 for bug 1396965

There is a more simple workaround: just make a clone of the volume - it should work even if the VM is running (The only problem is the data loss. So you'd better stop the VM before it).

For example:

openstack volume create --size 5 --source Vol Name

Should create a copy of the volume source Vol with 5 GB. Just note that the size should at least be equal to the source volume size, and the reference for the attached volume can be its ID or name (better the ID).

This should create a exact copy of the attached volume, without kill the VM or hacking the Cinder and Nova DataBase. :-D