[ovirt-users] add gluster cluster to deployed cluster

Hello People, I have a 3 node cluster this just has virt service deployed, how would I add gluster service to this. We have installed 2 extra disks in each node and they are running oVirt Node 4.2.5.1 After we have a gluster service running how easy would it be to migrate an existing engine to Self Hosted Engine? Thanks, Paul S.