VMware admits it over-specced storage servers for years • The Register

VMware has admitted that its guidance about the hardware needed to run its vSAN virtual storage arrays has been wrong for years.

“Hardware guidance for vSAN has historically been derived from synthetic testing,” Product Marketing Engineer Pete Koehler wrote last week, explaining that VMware used that approach because it allowed tests for performance “under the most extreme circumstances.”

Koehler said VMware has since revisited its testing regime because, “While useful, synthetic tests do not reflect the characteristics of real world workloads and the behavior of the storage system.” His team therefore “pored over telemetry data gathered from thousands of vSAN clusters running all types of production workloads” and found vSAN clusters use “much less RAM than expected” and “may use fewer