Update:
I identified that the ovirtmgt network configuration was out of whack on the non-functioning host.
Problem 1: The GUI will not allow me to set the network back to its proper state.
Problem 2: I accidentally changed the IP address of ovirtmgt network the host that was working, so both hosts are now down. Even though I set the IP address back to its original value, the cluster manager is unable to see the host that was working.
Until I rebooted, the host could ping out, but didn't respond to pings.
I am able to see the host console.
At this point I have no functioning hosts, so there is no access to the storage domain.
I suspect the solution to either issue will be the solution to both issues.
Thank you.