[libvirt] Operation not permitted when start vm

hi,all please look at the error. env: libvirt-0.10.2-18.el6_4.5.x86_64 2.6.32-358.6.2.el6.x86_64 centos6.4 Thread-6291::ERROR::2013-09-18 12:44:21,205::vm::683::vm.Vm::(_startUnderlyingVm) vmId=`24f7e975-9aa5-4a14-b0f0-590add14c8b5`::The vm start process failed Traceback (most recent call last): File "/us r/share/vdsm/vm.py", line 645, in _startUnderlyingVm self._run() File "/usr/share/vdsm/libvirtvm.py", line 1529, in _run self._connection.createXML(domxml, flags), File "/usr/lib64/python2.6/site-packages/vdsm/libvirtconnection.py", line 83, in wrapper ret = f(*args, **kwargs) File "/usr/lib64/python2.6/site-packages/libvirt.py", line 2645, in createXML if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self) libvirtError: internal error Process exited while reading console log output: char device redirected to /dev/pts/4 qemu-kvm: -drive file=/rhev/data-center/7828f2ae-955e-4e4b-a4bb-43807629dc52/d028d521-d4a9-4dd7-a0fe-3e9b60e7c4e4/images/ac025dc1-4e25-4b71-8c56-88dcb61b9f09/cae1bb2d-0529-4287-95a3-13dcb14f082f,if=none,id=drive-ide0-0-0,format=qcow2,serial=ac025dc1-4e25-4b71-8c56-88dcb61b9f09,cache=none,werror=stop,rerror=stop,aio=n ative: could not open disk image /rhev/data-center/7828f2ae-955e-4e4b-a4bb-43807629dc52/d028d521-d4a9-4dd7-a0fe-3e9b60e7c4e4/images/ac025dc1-4e25-4b71-8c56-88dcb61b9f09/cae1bb2d-0529-4287-95a3-13dcb14f082f: Operation not permitted