@MichaelCropper
Truenas on bare metal just as storage, XCP-NG is also bare metal on 3 hosts to make a pool. That's the minimum if you want to enable High Availability, it also works really well as a "normal" pool which is what I have.
Rolling Pool functions are great, click the button and the system moves the VMS off of the host that need updates, reboots, moves VMs off of the next host, repeat. Only works with Shared storage.