blog.richardmcdougall.com

Saving Joules

It’s been well talked up that consolidating physical systems can save a lot of datacenter engery — for example, consolidating 20 systems, all with 3-5% utilization can reduce power by up to 10-15x — or considered in more tractable terms, each server removed is equivalent to taking four cars off the road or planting 55 trees in a year.

Taking this concept further, the distributed power management feature in Virtual Infrastructure allows us to further reduce power by another 50%. Since load levels of typical applications aren’t constant, there are periods of the day where less servers are required — and in those periods, power can be saved by moving the remaining work onto fewer servers and powering down the unneeded capacity

A colleague put together this entertaining video, in which we measured the performance and watts consumed during typical peaky workload. The scenario is based on the email load curve typically observed — that peaks at 9am in the morning, and is at a minimum during the evening hours.