Note the reference to PR/SM - this is a hiper-visor, and manages the dispatching of LPARs.
Not an operating system per se, but has sufficient logic to facilitate dynamic dispatching and (LPAR) load balancing. Think of it as a microcode layer.
After-thought Hitachi have done this on blades as well - google virtage.
Last edited by syg00; 03-20-2008 at 07:19 AM.