I've setup a "Gluster Management" network in DC, cluster and all hosts. It is appearing as "operational" in the cluster and all host networks look correct. But I'm seeing this warning continually in the engine.log:

2016-05-27 08:56:58,988 WARN  [org.ovirt.engine.core.vdsbroker.gluster.GlusterVolumesListReturnForXmlRpc] (DefaultQuartzScheduler_Worker-80) [] Could not associate brick 'glustermount.host1:/gluster/data/brick' of volume '7a25d2fb-1048-48d8-a26d-f288ff0e28cb' with correct network as no gluster network found in cluster '00000002-0002-0002-0002-0000000002b8'