[libvirt] Error while adding volume through virsh

Hi, I was trying to add volume...I got one xml snippet and I modified it according to my node configuration: < volume> <name>testNode/cluster.vmdk </name> <allocation>0 </allocation> <capacity unit='G'>2<capacity> </volume> Now when I executed "virsh vol-create datastore1 /local/new_volume.xml" one error message came saying: "Error: Failed to create volume from /local/new_volume.xml" Error: internal error: Creation of raw volumes is not supported" Can anyone tell me what is going wrong here? Regards, Varun