[ovirt-users] Decommission Master Storage Domain

Hi guys, I've searched around a little but don't see much on how to do this. I'm running ovirt-engine-3.5.6.2-1.el6.noarch on Centos 6.x I have 4 x Centos 6.x hosts connected to an FC SAN with two different RAID arrays configured on it, one new RAID and one old RAID. The new RAID is shared as a new FC storage domain, the old RAID as my old Master storage domain. I have moved all VM's using LSM to the new storage domain and I would like to remove my old storage domain now, so that the old physical hard disks can be removed out of my SAN. If I go to "Disks" on the old storage domain I only see two named OVF_store etc, so it looks like it's ready to be decommissioned. How can I promote my new domain to the master and remove/destroy my old master domain and can it all be done without any VM downtime? Any help is greatly appreciated. Thanks! Regards. Neil Wilson.