Comment 6 for bug 1044135

It's odd to me that in your log file the last thing it printed was:

2012-08-30 16:49:03 DEBUG [quantum.agent.linux.utils] Running command: sudo ovs-vsctl --timeout=2 get Interface tap6d6f30fc-77 external_ids

(I would expect to see the something like this after that:
2012-08-30 16:49:03 DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ovs-vsctl', '--timeout=2', 'get', 'Interface', 'tap010d6c10-8e', 'external_ids']
Exit code: 0
Stdout: '{attached-mac="fa:16:3e:c9:98:20", iface-id="010d6c10-8ec9-438a-a02f-fab9eb333f01", iface-status=active}\n')

I'm surprised if that command is actually hanging. If you can reproduce this again when this happens can you do ps -eaf | grep ovs-vsctl to see if the ovs-vsctl command is hanging?

If the agent stops working ports will still attach to the bridge but won't be placed on a vlan.