Comment 20 for bug 1348204

This looks like what we'd want if bdm.connection_info is None, but this is down in the virt driver code:

http://git.openstack.org/cgit/openstack/nova/tree/nova/virt/block_device.py?id=2014.2.b3#n271

There is a lot of magic happening here and it's not clear to me what this is used for or why this isn't in the compute manager. I'm wondering if the block_device wrapper code in the virt driver is setting bdm.connection_info to None and updating that in the database in one part of the code and then when nova.compute.manager.detach_volume is called later it's None and we fail.

I'll push up some diagnostic logging patches to try and see what's going on.