I've followed the ubuntu OpenStack setup pretty much to the letter, and I'm able to launch the test cirros instance perfectly fine, however when I try to launch "trusty-server-cloudimg-amd64-disk1.img" it throws an error:

Error during following call to agent: ['ovs-vsctl', '--timeout=120', 'del-port', 'br-int', u'qvob81c197a-49']

Since it has to do with ovs-vsctl, I figured it was something on the network node, but there's no mention of it in the openvswitch log files on the network node.

I managed to get it launched using the m1.small flavor instead of m1.tiny

I guess the ubuntu image has some sort of requirement for the root disk size. I can live with that, but I'm just curious of the error.