Date Added: May 2010
The paper has implemented a commercial enterprise-grade system for providing fault-tolerant virtual machines, based on the approach of replicating the execution of a primary Virtual Machine (VM) via a backup virtual machine on another server. The paper has designed a complete system in VMware vSphere 4.0 that is easy to use, runs on commodity servers, and typically reduces performance of real applications by less than 10%. The method for replicating VM execution is similar to that described in Bressoud, but the author has made a number of significant design changes that greatly improve performance. In addition, an easy-to-use, commercial system that automatically restores redundancy after failure requires many additional components beyond replicated VM execution.