[ovirt-users] Recreating ISO storage domain

I have created a three host oVirt cluster using 4.4.2. I created an ISO storage domain to hold my collection of ISO images, and then decided to migrate it to a better location. I placed the storage domain in maintenance mode, end then removed it. When I when to recreate it add the new location, I found that the 'ISO' storage domain was no longer an options. What do I need to do to re-enable it, so I can re-create the storage domain.