VMware has released a High Availability Deployment Best Practices whitepaper for vSphere 4.1.
paper describes best practices and guidance for properly deploying VMware® High Availability (VMware HA) in VMware vSphere™ 4.1 (“vSphere”), including discussions on proper network and storage design, and recommendations on settings for host isolation response and admission control. This best-practice paper is not designed to replace existing product documentation. Instead it is designed to provide guidance based on the experience of VMware HA Product Management, Technical Marketing and Professional Services staff. Although
there are many configuration options to choose from and architecture choices that can be made, the recommendations in this paper are based on the most reliable and resilient possible choices for the majority of cluster deployments.