[ovirt-users] glusterfs

I currently have 3 nodes, one is the engine node and 2 Centos 7 hosts, and I plan to add another Centos 7 KVM host once I get all the vm's migrated. I have san storage plus the raid 5 internal disks. All OS are installed on mirrored SAS raid 1. I want to use the raid 5 vd's as exports, ISO and use the 4TB iscsi for the vm's to run on. The iscsi has snapshots hourly and over write weekly. So here is my question: I want to add glusterfs, but after further reading, that should have been done in the initial setup. I am not new to Linux, but new to Ovirt and need to know if I can implement glusterfs now or if it's a start from scratch situation. I really don't want to start over but would like the redundancy. Any advice is appreciated. Eric