Finnally !!!

Femi,  thank you so much !!! I wouldn't have been able do solve this without your help.

So,  just as info:

In this version ( iso ovirt-node-ng-installer-ovirt-4.2-2018053012 ) ,  multipah.conf seems to be alrady configured to blacklist all devices.

It already has configured :

# VDSM PRIVATE    - as second line and,

blacklist {
        devnode "*"
}

HE installation went fine, but after reboot the gluster volumes were not present - glusterd daemon was not enabled at boot, so the ansible playbook did not changed that.

Now, I am trying to figure out wat it would be the best procedure to create a new gluster volume on sdc drive,  and put some vms to run on it.

Cockpit UI won't let me,  because its asking for 3 nodes and "No two hosts can be the same" .

Should i just format the drive as xfs,  mount it ( fstab ) under /gluster_briks/spinning_storage,  create the gluster volume from cli and add it as a new storage domain ?

What it would be the best approach to accomplish this ?

Again, thank you very much  !