vSphere High Performance Cookbook

Memory performance best practices

Virtualization causes an increase in the amount of physical memory required, due to the extra memory needed by ESXi for its own code and data structures, and you need to know what are the best practice standards you have.

There are four basic principles, which you should keep in mind:

• Allocate enough memory to hold the working set of applications that you will run on the virtual machine, thus minimizing swapping. You can estimate the working set by monitoring the Active memory metric.
• Do not disable the balloon driver
• Keep transparent page sharing enabled. It's free!
• Avoid overcommitting memory to the point that it results in heavy memory reclamation, especially non-trivial Swap In rates (KBps).

How to do it…

So you ...