The green data center is turning out to be a more elusive beast than previously thought. It seems that while everyone wants one, no one is sure how to go about it or what technologies are truly green. In short, how do you measure "greenness?"
A new survey by Digital Realty Trust, a data-center management firm, reports that more than half of large enterprises (those with 5,000+ users) have green strategies in place, even though three-quarters of respondents are not able to define exactly what "green" means.
Part of the confusion no doubt lies in the fact that there are no benchmarks or other meaningful tools to evaluate power consumption and cooling practices across the enterprise. Sure, you can measure the draw on your servers, appliances and other individual pieces of hardware, but there is yet to be a reliable set of metrics to calculate overall energy efficiency, according to Aaron Hay at Info~Tech. Groups like The Green Grid and the Climate Savers Computing Initiative are working on the problem, but without an accurate way to measure usage, it will be very difficult for IT departments to convince the front office that green technology is worth the investment.
Part of this confusion stems from the fact that there is no clear-cut way to measure power consumption on the most basic computing element, the CPU. Current specs are based on the thermal design power metric, which looks at the energy needed to run the chip at full capacity. AMD has proposed an average CPU power metric (ACP) that looks at the energy needed to process industry benchmark workloads like TPC-C and SPEC CPU 2006. The problem is that not all chips are designed the same way and may generate misleading results. For example, an Intel quad may draw less power on paper because it lacks an integrated memory controller. Add that function to the overall chipset and overall consumption might very well increase.
In lieu of industry-wide benchmarks, there are a number of solutions aimed at measuring the conditions at individual datacenters with an eye toward improving heating and cooling efficiency. Sun just launched the Eco Responsibility Initiative, which includes the Eco Assessment Kit, Eco Optimization Kit and the Eco Virtualization Kit, as well as the Eco Services Suite designed to identify power and cooling problems and implement corrective actions.
And a company called SynapSense has developed a software kit and line of sensors that measure things like temperature, pressure and other conditions to provide an environmental map of the data center. IT can than experiment with systems revisions and new implementations using quantifiable results that can be used to justify additional investment or disprove manufacturers' claims.
In the end, we may simply have to come to the realization that you can never be green enough. No matter how well you do, there will always be someone saying you can do better. But at least with the ball rolling toward proper measurement techniques and benchmarks, you can at least tell if you're heading in the right direction.