The disk drive on the XEN server finally. I replaced it with a SSD and used the opportunity to install Oracle VM Server 3.4.6.
Burned V980620-01 to a DVD and installed OVM Server from there.
Because OVM Manager now requires 8 GB RAM, I decided against dedicating any of my existing desktops to be the OVM Manager, nor did I buy a whole new desktop just to run OVM Manager. I will contiune to use raw XEN under OVM Server.
Now recording my build in the GIT repository, xen_server_farm .