Can I do this? I have 4 Dell 1U rackmount servers with 4GB RAM each and a 3.0Ghz processor each, over a gigabit network can I get them to act as one server in Ubuntu or something like openmosix. Second if I can do that how do I get OS virtualization such as Xen to work on the cluster so I can run 10 VPS's over on 4 servers? So I can keep adding more 1u servers adding to the total computing 'power'.
Edit: Thanks for your responses, I will probably use Xen on the more powerful server then i will use the others for clustering using openMOSIX or Ubunutu's clustering.