There's a condition in instance migration + deletion, which I cannot define properly at the moment, but it results in the following state:
- instance host is already changed to the new host
- instance is still visible in the driver of the old host
- on nova-compute restart on the old host _destroy_evacuated_instances() fails at the _get_instance_nw_info() step with exception "InstanceNotFound: Instance c04a5ef9-e908-470b-9e49-0107d6327829 could not be found." from the network manager
There should be two fixes here really:
1. make _destroy_evacuated_instances() more robust so it doesn't crash the whole nova-compute in such case
2. find out how that state was created and stop it from occurring
Just to clarify previous description the issue is that the list from the driver includes instances which are already marked as deleted. Getting an instance by uuid via _get_instance_ nw_info( ) does not look through those.
This could be most likely resolved in a similar way to what happens to instances which are reaped.