Several hardware-based techniques that support checkpoint and rollback recovery are presented. The focus is on hardware schemes for uniprocessors, shared-memory multiprocessors, and distributed virtual-memory systems. A taxonomy for processor and memory techniques based on the memory hierarchy is presented. This provides a basis for understanding subtle differences among the various schemes. Processor-based schemes that handle transient faults by using processor-based transparent rollback techniques and memory-based schemes that roll back data instead of instructions and can be integrated with the processor techniques or can be exploited by higher levels of software are discussed.