[ovirt-users] Help moving hosted_storage data/domain

Hi there, first time here. I successfully installed Oracle Linux Virtual Manager that's basically Ovirt 4.6. I have a datacenter, 2 separate cluster, 3 host per cluster (self hosted engine configuration). During the installation process I defined the nfs storage for the hosted engine VM, and now I'm in trouble. I can shut down any host but the one that serve the nfs. I understand lately that I need a distributed storage to obtain HA, then I added the glusterfs support. I can see my gluster volume but I can't add it as storage domain. It's simply doesn't appear in dropdown menu when I try to add it as new storage domain. A part for that: there's a way to move data from hosted_storage domain (the nfs one) to another one? I try to setup another one as main but no joy. If a try to move the disk from there it's say to me I can't. I searched on the web but I found several answers, starting from: "no you can't" to "with engine-backup utility" and I'm quite confused. Reinstall it isn't an option, i have approx 60 vm active. Any help it's appreciated. (forgive eventually mistakes, I'm not a native). Maurizio