Chris I've seen this happen when the server can't resolve its own hostname, resulting in extra output in the sudo commands that nova uses to create nbd devices; is that potentially happening in your case as well?
** Changed in: nova (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to nova in Ubuntu. https://bugs.launchpad.net/bugs/1287666 Title: qemu-nbd processes left behind after instance deletion To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nova/+bug/1287666/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs