Hypervisor-based fault tolerance

Abstract

Protocols to implement a fault-tolerant computing system are described. These protocols augment the hypervisor of a virtual-machine manager and coordinate a primary virtual machine with its backup. No modifications to the hardware, operating system, or application programs are required. A prototype system was constructed for HP's PA-RISC instruction-set architecture. Even though the prototype was not carefully tuned, it ran programs about a factor of 2 slower than a bare machine would.