Comment 9 for bug 1746972

How to reproduce this error:
1. Create an instance from the image with property hw_qemu_guest_agent=yes and installed qemu-guest-agent inside.
2. Stop qemu-guest-agent inside this instance.
```
...
root 1450 0.0 0.0 21972 188 ? Ss 14:02 0:00 /usr/sbin/qemu-ga --daemonize -m virtio-serial -p /dev/virtio-ports/org.qemu.guest_agent.0
...
root@francoise:~# service qemu-guest-agent stop
```
3. Try to change password with ``nova set-password``.
4. See, that instance goes to ERROR state, but continues to run.
Trace: http://paste.openstack.org/show/731375/