I am using ubuntu 12.04, 64 bit. I have installed keystone and glance successfully. After I installed nova and tried to run all the nova-* services. nova-compute gave me error like this:

2012-05-23 18:08:41 CRITICAL nova [-] Failed to connect socket to '/var/run/libvirt/libvirt-sock': Permission denied 2012-05-23 18:08:41 TRACE nova Traceback (most recent call last): 2012-05-23 18:08:41 TRACE nova File "/usr/local/bin/nova-compute", line 7, in <module> 2012-05-23 18:08:41 TRACE nova execfile(__file__) 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/bin/nova-compute", line 49, in <module> 2012-05-23 18:08:41 TRACE nova service.wait() 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/service.py", line 448, in wait 2012-05-23 18:08:41 TRACE nova _launcher.wait() 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/service.py", line 148, in wait 2012-05-23 18:08:41 TRACE nova service.wait() 2012-05-23 18:08:41 TRACE nova File "/usr/lib/python2.7/dist-packages/eventlet/greenthread.py", line 166, in wait 2012-05-23 18:08:41 TRACE nova return self._exit_event.wait() 2012-05-23 18:08:41 TRACE nova File "/usr/lib/python2.7/dist-packages/eventlet/event.py", line 116, in wait 2012-05-23 18:08:41 TRACE nova return hubs.get_hub().switch() 2012-05-23 18:08:41 TRACE nova File "/usr/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 177, in switch 2012-05-23 18:08:41 TRACE nova return self.greenlet.switch() 2012-05-23 18:08:41 TRACE nova File "/usr/lib/python2.7/dist-packages/eventlet/greenthread.py", line 192, in main 2012-05-23 18:08:41 TRACE nova result = function(args, *kwargs) 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/service.py", line 109, in run_server 2012-05-23 18:08:41 TRACE nova server.start() 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/service.py", line 194, in start 2012-05-23 18:08:41 TRACE nova self.manager.update_available_resource(ctxt) 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/compute/manager.py", line 2441, in update_available_resource 2012-05-23 18:08:41 TRACE nova self.driver.update_available_resource(context, self.host) 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/virt/libvirt/connection.py", line 2065, in update_available_resource 2012-05-23 18:08:41 TRACE nova 'vcpus_used': self.get_vcpu_used(), 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/virt/libvirt/connection.py", line 1889, in get_vcpu_used 2012-05-23 18:08:41 TRACE nova for dom_id in self._conn.listDomainsID(): 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/virt/libvirt/connection.py", line 283, in _get_connection 2012-05-23 18:08:41 TRACE nova self.read_only) 2012-05-23 18:08:41 TRACE nova File "/opt/stack/nova/nova/virt/libvirt/connection.py", line 326, in _connect 2012-05-23 18:08:41 TRACE nova return libvirt.openAuth(uri, auth, 0) 2012-05-23 18:08:41 TRACE nova File "/usr/lib/python2.7/dist-packages/libvirt.py", line 102, in openAuth 2012-05-23 18:08:41 TRACE nova if ret ... (more)