Testing the performance capabilities of the vSAN cluster helps to confirm that the configuration is sound. Many of the traditional methodologies used for testing storage subsystems in a vSphere environment are supported with vSAN. The tests differ when analyzing vSAN performance. Tools such as vSAN Observer can be used to provide a more in-depth level of detail.

For optimal performance, VMware recommends that the active working set of the virtual machine fit into the flash acceleration layer of vSAN. Measuring the active working set of a virtual machine is not straightforward, but a good conservative estimate is 10 percent of the used capacity, not taking into account capacity utilized for the Number of Failures-to-Tolerate redundancy policy assigned to the virtual machine.