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Hi all,

I posted this on the IRC channel but got no response, so I'll try here.

Suppose I do the following:

1) create an instance (instance files not on shared storage)
2) kill its compute node and evacuate the instance to another node
3) boot up the original compute node
4) kill the second compute node and evacuate back to the first compute node

In step 4 it seems to be failing a check in rebuild_instance() because 
it finds the old instance file on the disk at/var/lib/nova/instances/. 
  Is this a bug?  If not, what's the intended behaviour in this case? 
Surely the admin isn't supposed to manually wipe a compute node before 
reconnecting it to the network...

It seems to me that when the original compute node boots up it should 
recognize that the instance has been evacuated and delete the instance 
file on the disk.

Or is the problem that it doesn't know whether the instances are on 
shared storage (in which case we wouldn't want to delete the instance 
file) or local storage (in which case we would)?  If this is the case, 
then maybe we should embed the storage type in the instance itself--this 
would also let us avoid having to manually specify --on-shared-storage 
in the "evacuate" call.

Thanks,
Chris