ESXi 4.1 migration guide
VMware ESXi is VMware’s next generation hypervisor architecture and is designed to improve hypervisor management in the areas of security, deployment and configuration, and ongoing administration. In the vSphere 4.1 release VMware has added significant enhancements to either ESXi or the core tools that are used to manage ESXi. This paper describes the architecture of ESXi and then explains how various management tasks are performed in ESXi 4.1. This information can be used to help plan a migration to the ESXi architecture from the legacy ESX framework.