[justlurking]

Notice there is not a disk in each node? The nodes boot the kernel either from floppy or NVRAM, use ARP/RARP to get an IP address, NFS mount their file system, and then boot the rest of the OS including multiprocessing bits like PVM and MPI over NFS (Network File Share, a UNIX RPC protocol)

No, there is no floppy. I believe the MSI motherboard BIOS can be configured to boot from a network address: I built a system with a different MSI motherboard earlier this year for someone else and noticed it the functionality.

[adam_az]

Yup, then they flashed the kernel into nvram. To boot from a network address, you have to have enough driver loaded alreadyfor the ethernet card and network file system mount functionality to work. For a Beowulf, you have to compile this stuff directly into the kernel, and not use loadable modules.