Using NFS as a backend of nova instances

Issue

• Trying to setup an NFS share that nova can use for instances under /var/lib/nova/instances

• When I launched a new VM on this node but get error . compute.log attached .I suspect this is permission connected problem .
  I tried to change ownership of the /var/lib/nova/instances but got the error below:

2014-04-13 08:31:49.797 3614 ERROR nova.openstack.common.rpc.amqp [req-01527f5a-1d45-4ecd-a187-284d680bdd90 802295dc58e548e6b232de8e249f957e d9cfdf37dd9f4dde9c5495474f7c1ba6] Exception during message handling
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp Traceback (most recent call last):
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/openstack/common/rpc/amqp.py", line 461, in _process_data
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     **args)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/openstack/common/rpc/dispatcher.py", line 172, in dispatch
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     result = getattr(proxyobj, method)(ctxt, **kwargs)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/exception.py", line 90, in wrapped
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     payload)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/exception.py", line 73, in wrapped
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     return f(self, context, *args, **kw)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 243, in decorated_function
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     pass
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 229, in decorated_function
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     return function(self, context, *args, **kwargs)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 294, in decorated_function
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     function(self, context, *args, **kwargs)
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 271, in decorated_function
014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     e, sys.exc_info()) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 258, in decorated_function 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     return function(self, context, *args, **kwargs) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1630, in run_instance 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     do_run_instance() 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/openstack/common/lockutils.py", line 246, in inner 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     return f(*args, **kwargs) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1629, in do_run_instance 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     legacy_bdm_in_spec) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 968, in _run_instance 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     notify("error", msg=unicode(e))  # notify that build failed 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 952, in _run_instance 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     instance, image_meta, legacy_bdm_in_spec) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1043, in _build_instance 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     set_access_ip=set_access_ip) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1426, in _spawn 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     LOG.exception(_('Instance failed to spawn'), instance=instance) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1423, in _spawn 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     block_device_info) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 2091, in spawn 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     block_device_info, context=context) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3249, in _create_domain_and_network 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     domain = self._create_domain(xml, instance=instance, power_on=power_on) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3192, in _create_domain 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     domain.XMLDesc(0)) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3187, in _create_domain 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     domain.createWithFlags(launch_flags) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 179, in doit 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     result = proxy_call(self._autowrap, f, *args, **kwargs) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 139, in proxy_call 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     rv = execute(f,*args,**kwargs) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 77, in tworker 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     rv = meth(*args,**kwargs) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp   File "/usr/lib64/python2.6/site-packages/libvirt.py", line 708, in createWithFlags 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp     if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self) 
2014-04-13 08:31:49.797 3614 TRACE nova.openstack.common.rpc.amqp libvirtError: Unable to pre-create chardev file '/var/lib/nova/instances/a64d1764-8b49-4c35-976c-9728b57ef3cc/console.log': Permission denied