Well, I have plans for a cluster system, that connects all the hardware together into one multimotherboarded system. I know that I won't get the cluster on Xen alone (as each Xen domain can only operate on a single CPU, be it real or virtual). I plan to use LAM MPI for the main clustering portion. Though I've noticed on PCI addresses, for the most part on PCI:00:XX:XX and PCI:01:XX:XX are the only ones used. is the first byte reserved with anything above PCI:01:XX:XX, or could I modify some stuff on the Xen source so that other computers in the network appear as PCI:02:XX:XX for slave node 1, PCI:03:XX:XX for slave node 2, PCI:04:XX:XX for slave node 3, etc.? That is modify it without breaking some standard that I don't even know what term to propperly google it. I am asking in UNIX rather than hardware because I am pretty sure `lspci` and `dmesg | less` are POSIX.1 specific systems of looking up hardware. edit: this may be a little confusing, I want the PCI devices for the slave nodes to show up on atleast the head node. I was wondering if I could cheat by using addresses that do not appear to have associations made to them yet.