escription of problem:

When launching new instances  80% fails with the following error:

2016-04-07 15:54:38.095 24791 DEBUG nova.compute.utils [req-08f5df02-353e-460e-8487-b203d10b78dc 986d81f31c2c4949a04925e2149d6926 1f69bd2b614a403a8a42afeb36fd67db] [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4] Virtual Interface creation failed notify_about_instance_usage /usr/lib/python2.7/site-packages/nova/compute/utils.py:336
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4] Traceback (most recent call last):
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1272, in _run_instance
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     instance, image_meta, legacy_bdm_in_spec)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1416, in _build_instance
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     network_info.wait(do_raise=False)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     six.reraise(self.type_, self.value, self.tb)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1392, in _build_instance
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     set_access_ip=set_access_ip)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 418, in decorated_function
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     return function(self, context, *args, **kwargs)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1810, in _spawn
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     LOG.exception(_('Instance failed to spawn'), instance=instance)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     six.reraise(self.type_, self.value, self.tb)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1807, in _spawn
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     block_device_info)
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2408, in spawn
2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]     block_device_info)


2016-04-07 15:54:38.095 24791 TRACE nova.compute.utils [instance: 127f0361-fa13-409f-93e5-dd5dea6581f4]   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 3947, in _create_domain_annd_network   


Environment:

Openstack Routers but dedicated ones, all networks are defined with segmentation_id=vlan, all vlans are connected in the Juniper L3 switch VRF that takes care of the routing/firewalling so we don't use any l3agent.



Version-Release number of selected component (if applicable):


openstack-neutron-2014.1.5-4.el7ost.noarch
openstack-neutron-openvswitch-2014.1.5-4.el7ost.noarch
openstack-nova-api-2014.1.5-5.el7ost.noarch
openstack-nova-common-2014.1.5-5.el7ost.noarch
openstack-nova-compute-2014.1.5-5.el7ost.noarch



How reproducible:
80%


Steps to Reproduce:
1. Launch an instance
2.
3.

Actual results:
- the specified trace
- instace doesn't start

Expected results:
Instance starts

Additional info: