创建实例报错找不到有效的宿主机,请大家帮帮忙,谢谢

搭建了一个两节点的openstack平台,一个控制节点,一个计算节点,单网卡,网络用的nova-network,
计算节点网络配置:
auto eth0
iface eth0 inet static
auto br100
iface br100 inet static
address 10.21.1.200
netmask 255.255.0.0
gateway 10.21.0.98
broadcast 10.21.255.255
network 10.21.0.0
bridge_ports eth0
bridge_fd 0
bridge_stp off
控制节点网络配置:
auto eth0
iface eth0 inet static
address 10.21.1.228
netmask 255.255.0.0
gateway 10.21.0.98
broadcast 10.21.255.255
network 10.21.0.0
用这个命令创建了一个虚拟网络:
nova network-create demo-net --bridge br100 --multi-bost T --fixed-range-v4 203.0.113.24/29
日志中说eth0已经被用了,和这个命令有关系吗.
log日志
2016-04-02 15:09:16.938 1668 INFO oslo.messaging._drivers.impl_rabbit [req-e4325055-13bd-42bd-8b7e-7044ae71fac9 ] Connecting to AMQP server on controller:5672
2016-04-02 15:09:17.291 1668 INFO oslo.messaging._drivers.impl_rabbit [req-e4325055-13bd-42bd-8b7e-7044ae71fac9 ] Connected to AMQP server on controller:5672
2016-04-02 15:09:59.960 1668 ERROR nova.scheduler.utils [req-e4325055-13bd-42bd-8b7e-7044ae71fac9 None] [instance: 522b3711-f3a9-4568-bec8-7f1ba77cbbdd] Error from last host: guo-OptiPlex-3020 (node guo-OptiPlex-3020): [u'Traceback (most recent call last):\n', u'  File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2109, in _do_build_and_run_instance\n    filter_properties)\n', u'  File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2240, in _build_and_run_instance\n    instance_uuid=instance.uuid, reason=six.text_type(e))\n', u'RescheduledException: Build of instance 522b3711-f3a9-4568-bec8-7f1ba77cbbdd was re-scheduled: Failed to add interface: sudo: unable to resolve host guo-OptiPlex-3020\ndevice eth0 is already a member of a bridge; can\'t enslave it to bridge br100.\n\nTraceback (most recent call last):\n\n  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 134, in _dispatch_and_reply\n    incoming.message))\n\n  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 177, in _dispatch\n    return self._do_dispatch(endpoint, method, ctxt, args)\n\n  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 123, in _do_dispatch\n    result = getattr(endpoint, method)(ctxt, **new_args)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/floating_ips.py", line 114, in allocate_for_instance\n    **kwargs)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 511, in allocate_for_instance\n    requested_networks=requested_networks)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 192, in _allocate_fixed_ips\n    vpn=vpn, address=address)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 967, in allocate_fixed_ip\n    exc_info=True)\n\n  File "/usr/lib/python2.7/dist-packages/nova/openstack/common/excutils.py", line 82, in __exit__\n    six.reraise(self.type_, self.value, self.tb)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 943, in allocate_fixed_ip\n    self._setup_network_on_host(context, network)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1816, in _setup_network_on_host\n    self._initialize_network(network)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1480, in _initialize_network\n    self.l3driver.initialize_gateway(network)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/l3.py", line 105, in initialize_gateway\n    gateway=(network_ref[\'gateway\'] is not None))\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 1404, in plug\n    return _get_interface_driver().plug(network, mac_address, gateway)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 1453, in plug\n    network, gateway)\n\n  File "/usr/lib/python2.7/dist-packages/nova/openstack/common/lockutils.py", line 272, in inner\n    return f(*args, **kwargs)\n\n  File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 1568, in ensure_bridge\n    raise exception.NovaException(msg)\n\nNovaException: Failed to add interface: sudo: unable to resolve host guo-OptiPlex-3020\ndevice eth0 is already a member of a bridge; can\'t enslave it to bridge br100.\n\n\n']
2016-04-02 15:10:00.103 1668 WARNING nova.scheduler.driver [req-e4325055-13bd-42bd-8b7e-7044ae71fac9 None] [instance: 522b3711-f3a9-4568-bec8-7f1ba77cbbdd] NoValidHost exception with message: 'No valid host was found.'
2016-04-02 15:10:00.103 1668 WARNING nova.scheduler.driver [req-e4325055-13bd-42bd-8b7e-7044ae71fac9 None] [instance: 522b3711-f3a9-4568-bec8-7f1ba77cbbdd] Setting instance to ERROR state.


情况大概是这样了.哪位大神帮帮忙啊,这个问题一直解决不了

这个还真看不出来。
出现这个问题原因也很多。
比如下面很多跟楼主类似的问题

新手求助！无法启动实例
http://www.aboutyun.com/forum.php?mod=viewthread&tid=14924
【已解决】启动云主机时，No valid host was found.

http://www.aboutyun.com/forum.php?mod=viewthread&tid=11203

其实最终还是配置的问题，也有可能是打错字等造成的。原因来讲找不到有效的host。
比如网络配置问题，Nova配置问题等。