Description of problem: Deploying RHOS 15 with mentioned topology and running the following tempest test, gives failures:
tempest.api.compute.servers.test_device_tagging.TaggedAttachmentsTest.test_tagged_attachment


Version-Release number of selected component (if applicable):
core_puddle: RHOS_TRUNK-15.0-RHEL-8-20190607.n.1

How reproducible: always

Topology: 1 controller, 2 compute

Steps to Reproduce:
1. Deploy RHOS 15 with mentioned topology
2. Run the following tempest test:
 tempest.api.compute.servers.test_device_tagging.TaggedAttachmentsTest.test_tagged_attachment

Actual results:
 Response - Headers: {'content-length': '0', 'x-openstack-request-id': 'req-2397e0e9-c4a4-436a-9c46-cfac8619301b', 'date': 'Tue, 11 Jun 2019 04:33:19 GMT', 'connection': 'close', 'status': '204', 'content-location': 'http://10.0.0.129:9696/v2.0/subnets/9e98d3cf-9afc-40d3-a1ab-e290bbcede93'}
        Body: b''
2019-06-11 04:33:21,844 253873 INFO     [tempest.lib.common.rest_client] Request (TaggedAttachmentsTest:_run_cleanups): 204 DELETE http://10.0.0.129:9696/v2.0/networks/5ae254fc-6068-4c1f-bcee-c240037d7ed7 2.054s
2019-06-11 04:33:21,844 253873 DEBUG    [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'content-length': '0', 'x-openstack-request-id': 'req-3538e67b-32ce-4982-9bf2-0594bca57b3e', 'date': 'Tue, 11 Jun 2019 04:33:21 GMT', 'connection': 'close', 'status': '204', 'content-location': 'http://10.0.0.129:9696/v2.0/networks/5ae254fc-6068-4c1f-bcee-c240037d7ed7'}
        Body: b''
}}}

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/tempest/common/utils/__init__.py", line 89, in wrapper
    return f(*func_args, **func_kwargs)
  File "/usr/lib/python3.6/site-packages/tempest/api/compute/servers/test_device_tagging.py", line 359, in test_tagged_attachment
    networks=[{'uuid': self.get_tenant_network()['id']}])
  File "/usr/lib/python3.6/site-packages/tempest/api/compute/base.py", line 246, in create_test_server
    **kwargs)
  File "/usr/lib/python3.6/site-packages/tempest/common/compute.py", line 265, in create_test_server
    server['id'])
  File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 220, in __exit__
    self.force_reraise()
  File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
    six.reraise(self.type_, self.value, self.tb)
  File "/usr/lib/python3.6/site-packages/six.py", line 675, in reraise
    raise value
  File "/usr/lib/python3.6/site-packages/tempest/common/compute.py", line 236, in create_test_server
    clients.servers_client, server['id'], wait_until)
  File "/usr/lib/python3.6/site-packages/tempest/common/waiters.py", line 76, in wait_for_server_status
    server_id=server_id)
tempest.exceptions.BuildErrorException: Server 6f293264-0b0c-4069-8198-3bef309d00e7 failed to build and is in ERROR status
Details: {'code': 500, 'created': '2019-06-11T04:33:14Z', 'message': 'Exceeded maximum number of retries. Exhausted all hosts available for retrying build failures for instance 6f293264-0b0c-4069-8198-3bef309d00e7.'}


Expected results:
Test passed

Additional info: