openstack实例启动失败

创建实例失败，查看compute.log，如下异常：

 libvirtError: internal error Process exited while reading console log output: chardev: opening backend "file" failed

ERROR nova.compute.manager [req-14367115-a9db-49d9-a4b6-f0aa2b10b126 264de00cea3348cda1b968f31b369e92 ac0da7079c8d4bc2b95009175b21fa66] [instance: 3f5ba1a1-c64c-4d18-8c52-3efb5f162ba0] Build error: ['Traceback (most recent call last):\n', '  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 494, in _run_instance\n    injected_files, admin_password)\n', '  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 747, in _spawn\n    block_device_info)\n', '  File "/usr/lib/python2.6/site-packages/nova/exception.py", line 117, in wrapped\n    temp_level, payload)\n', '  File "/usr/lib64/python2.6/contextlib.py", line 23, in __exit__\n    self.gen.next()\n', '  File "/usr/lib/python2.6/site-packages/nova/exception.py", line 92, in wrapped\n    return f(*args, **kw)\n', '  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 1092, in spawn\n    block_device_info)\n', '  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 1931, in _create_domain_and_network\n    domain = self._create_domain(xml)\n', '  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 1910, in _create_domain\n    domain.createWithFlags(launch_flags)\n', '  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 187, in doit\n    result = proxy_call(self._autowrap, f, *args, **kwargs)\n', '  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 147, in proxy_call\n    rv = execute(f,*args,**kwargs)\n', '  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 76, in tworker\n    rv = meth(*args,**kwargs)\n', '  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 708, in createWithFlags\n    if ret == -1: raise libvirtError (\'virDomainCreateWithFlags() failed\', dom=self)\n', 'libvirtError: internal error Process exited while reading console log output: chardev: opening backend "file" failed\n\n']

异常显示libvirt无法读取console.log(/var/lib/nova/INSTANCE/compute.log)文件，修改/etc/libvirt/qemu.conf，注释

# user = "root"

#group = "root"

#dynamic_ownership = 1

然后重启libvirt，/etc/init.d/libvirtd restart

文件本事是注释掉的，是我在群里问其他问题时，别人建议我去掉注释的，以后问问题要想为什么