[rhos-list] nova compute not starting

[Dan Smith]

> Moving it back and restarting nova-compute now gives me just the "not
> found in database errors" and no other errors.

Nova expects to own the system, yeah. However, it _is_ tolerant of other
VMs on the system if you configure it to be (otherwise it will delete
them when it finds them). The problem you experienced before was
probably due to the fact that nova uses libvirt, running under its user.
When it went to list or examine the VMs on the system, libvirt failed to
access some of those files and nova died, expectedly, as a result.

You can leave the other VMs on the system, but you will get (harmless)
warnings from Nova about them being there.

--Dan