I'm in the process of deploying an Openstack cloud and I've been aiming at maximize the number of computing node and in order to do that I've thought of using Ceph distributed storage and use an All in one openstack deployment, so that swift objects and glance's blocks are stored through Ceph. I have a total of 12 servers, so I'll end up with 1 Controller node for openstack services and use the remaining nodes for ceph cluster and computing.

Is it worth it to use a ceph storage system , and what would be the minimum number of nodes required to deploy it.