(nova): TRACE: Traceback (most recent call last):
(nova): TRACE:   File "/usr/bin/nova-network", line 49, in <module>
(nova): TRACE:     service.wait()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/service.py", line 404, in wait
(nova): TRACE:     _launcher.wait()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/service.py", line 118, in wait
(nova): TRACE:     service.wait()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/eventlet/greenthread.py", line 166, in wait
(nova): TRACE:     return self._exit_event.wait()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/eventlet/event.py", line 116, in wait
(nova): TRACE:     return hubs.get_hub().switch()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 177, in switch
(nova): TRACE:     return self.greenlet.switch()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/eventlet/greenthread.py", line 192, in main
(nova): TRACE:     result = function(*args, **kwargs)
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/service.py", line 88, in run_server
(nova): TRACE:     server.start()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/service.py", line 148, in start
(nova): TRACE:     self.manager.init_host()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1581, in init_host
(nova): TRACE:     self.driver.ensure_metadata_ip()
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 458, in ensure_metadata_ip
(nova): TRACE:     run_as_root=True, check_exit_code=[0, 254])
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 818, in _execute
(nova): TRACE:     return utils.execute(*cmd, **kwargs)
(nova): TRACE:   File "/usr/lib/python2.7/dist-packages/nova/utils.py", line 225, in execute
(nova): TRACE:     cmd=' '.join(cmd))
(nova): TRACE: ProcessExecutionError: Unexpected error while running command.
(nova): TRACE: Command: sudo ip addr add 169.254.169.254/32 scope link dev lo
(nova): TRACE: Exit code: 2
(nova): TRACE: Stdout: ''
(nova): TRACE: Stderr: 'RTNETLINK answers: File exists\n'