Comment 8 for bug 1560965

Actually, I don't see that as a duplicate.
What I'm describing is the failure to launch an instance at all if you choose to boot it from volume on Xen hypervisor. Attaching volumes to running instances works fine, so it's not related to cinder.
The cause is a default device name 'vda' in the file launch-instance-model.service.js. To let nova choose the device name it should be empty as default, which works as you can see in my tests. I will remove the duplicate mark from this bug.