Recently we decided to switch the ISP and therefore a new server needed to be set up. Since Xen runs great we figured to stick with it. Unfortunately not many Linux distributions support Xen so we ended up with XenServer Free from Citrix.
Our new ISP of course does not offer an automated installation for XenServer
but quite a lot of other options (even an outdated OpenBSD). The first approach
to sneak in XenServer was by installing some random Linux distribution,
mounting the second hard drive and using KVM to install it there. Afterwards
chainloader entry in Grub would save the day. At least in theory
since it failed in practise. With all hope lost on that approach surfing the
web to look for suitable solutions seemed the right way to continue in this
Luckily someone had the exact the same problem and came up with a clever solution (german): Launching the unattended installer via Grub. Infact it worked like a charm.