I installed a fresh engine on CentOS 6.5, and 3.5 nodes on two nested VMs. A significant portion of the day was spent testing basic Node functionality to ensure we didn't have any more SELinux denials, install problems on EFI, or other issues, after which I moved onto engine. DR was simply tested by pulling the network cable in the middle of an operation, disconnecting both nodes and waiting for storage arbitration to succeed, and uncleanly terminating the VM running engine then restarting. Backup and restore was tested with ovirt-engine-backup (which I haven't used before, and is quite nice).