Many of our customers have already virtualized Microsoft Exchange 2003 on VMware ESX Server 3. For customers who are considering virtualizing Exchange and want to know what to expect in terms of performance, we’ve published a whitepaper on the performance of Exchange in a virtual environment: http://www.vmware.com/pdf/Virtualizing_Exchange2003.pdf
The paper presents the results of a joint study with Dell that examined the performance implications of a virtualized Exchange environment. Specifically, we looked at:
- The performance implications of running Exchange Server 2003 on a virtual machine versus a physical system.
- The performance of Exchange Server 2003 in virtual machine configurations when “scaling-up” (adding more processors to a machine) and “scaling-out” (adding more machines).
The details of the configurations and results of the above experiments are documented in the white paper.
To briefly summarize, the results from the study indicate that on an Dell PowerEdge 6850 server configured with four 2.66 GHz dual-core Intel Xeon 7020 processors and 16GB of RAM.
- A uniprocessor virtual machine can support up to 1,300 Heavy Exchange users.
- Consolidating multiple instances of these uniprocessor Exchange virtual machines can cumulatively support up to 4,000 Heavy users while still providing acceptable performance and scaling.
- Uniprocessor virtual machines are, from a performance perspective, equivalent to half as many multiprocessor (two virtual processors) virtual machines.