[Users] HA and Live Migration FS Recommendations

Hi guys, I'm very new to oVirt and I have some questions that I can't seem to find answers for, so please go easy on me. We are looking at implementing a HA KVM virtualization environment over two(3 in total at a later stage) physical nodes using oVirt for about 8 guests using Centos 6.2. What I am looking at doing is using a fibre channel SAN to implement shared storage by allowing both physical nodes to see the same LUN on the SAN so that both physical nodes will have access to a shared filesystem for storing guest images on. I've opted for the shared LUN/storage approach to allow for HA and live migration of guests between the physical nodes. Do I need to configure GFS2 before oVirt so that both physical nodes can have access to the same LUN for the guest images; or will oVirt automatically handle locking/fencing etc. on the common filesystem? I've tried using luci/ricci to setup a "storage" cluster using GFS2 with oVirt mounting the GFS2 filesystem as a local directory, but this seems far from ideal. Any advice is appreciated. Thank you. Regards. Neil.