With the release of Microsoft® Windows Server 2008 Hyper-V there is a growing interest in deploying Exchange Server 2007 in virtualized environments. In a physical deployment, Microsoft recommends a maximum of 8 CPU cores and 32 GB of memory for a single Exchange Server 2007 Mailbox Server. In a virtualized environment, Exchange users can consolidate multiple Exchange Server Mailbox roles on a single physical server to take advantage of unused CPU cycles or available memory. Additional Exchange roles can be hosted on separate virtual machines (VM) and consolidated on a smaller number of physical servers to reduce hardware costs. Benefits of running Exchange in a virtualized environment can be multi-fold but will differ from one customer to the next.

In this paper, various configurations of Exchange Server 2007 are tested in physical and virtual environments to evaluate the performance scalability and to understand the sizing requirements for Exchange Server 2007 in a virtualized environment. Performance is measured for a Mailbox Server configured within a virtual machine hosting 1000 to 4000 Mailboxes. A consolidation of multiple exchange server roles and infrastructure servers simulating a small to medium deployment is performed as well. Finally some of the supported configurations from Microsoft are reviewed and best practices based on supported configurations are discussed.