Capacity planning provides a rather complex answer to a fairly simple question: How many virtual machines can I run on a given piece of server hardware? Answering this question is critical for immediate purchasing decisions and for setting a longer-term agenda for purchases that will scale the virtual infrastructure for future virtualizations.
This note explores some of the considerations in capacity planning and infrastructure sizing that need to be included in a capacity planning exercise, including:
- Estimating the number of virtual machines that can run per processor or per processor core.
- Consideration of balancing workloads across virtual host servers.
- Benchmarking new hardware for virtual infrastructure capacity.
Server sizing for capacity planning can appear to be more art than science. The results are high confidence estimates that will be proved out by actual implementation. However, having the best possible estimates is critical to gauging the hardware investment required to build a resilient and capable virtual infrastructure.
