Error: Failed to launch instance "server1.test.local": Please try again later [Error: No valid host was found. Exceeded max scheduling attempts 3 for instance 43a2c6a1-b04e-4791-bb03-0a5b892dcb44. Last exception: [u'Traceback (most recent call last):\n', u' File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2054, in _do].