There are approximately 4.75 million servers worldwide being run, managed and upgraded without being actively used on a daily basis. Those unused servers cost $20.7 billion to run, plus consume another $3.7 billion in energy costs. Furthermore, around $21.4 billion is wasted each year on hardware, maintenance, management, energy and cooling for unused servers. This is roughly equal to the cost of the Apollo space program.
Managing energy actively results in 40 percent or more energy savings in the data center. When you consider that a data center can consume 10 to 100 times more energy per square foot than the average office building, and in some cases up to 40 percent of an organization's carbon footprint, it is clear that managing energy in the data center is of paramount importance.
Data center executives generally do not have comprehensive management tools for monitoring and controlling energy. As a result, there's a lack of systematic analysis of energy strategies to determine which will yield the greatest benefits or pose the greatest risk to ongoing operations. This impedes the decision making process, leaving many guessing or adopting ad-hoc strategies. Once you begin measuring the energy in your data center, you can expose the biggest offenders (high energy consumers), come up with a plan to reach your goals, implement this plan and document your progress.
These are some of the most common ways data center energy management reduces energy consumption:
1. Detecting unused equipment and turning it off or recommissioning it. 15-20 percent of all servers are never used. Idle servers still consume about three-quarters of the energy of a server at 100 percent utilization. However, most data centers do not have tools to uncover unused equipment. Look for an energy management solution that enables you to detect all idle or rogue machines and make decisions using a per-asset cost analysis.
2. Virtualization. A recent survey found that among data centers that claimed to have completed their virtualization process, only about 35 percent of their servers had been virtualized. In other words, this survey revealed that picking servers that are suitable for virtualization is still a very ad-hoc process. An energy management solution can profile assets and give data center executives a per-asset cost and utilization picture of the data center. Virtualization can then be geared toward assets with low-utilization or high energy consumption in a planned effort.
3. Storage consolidation. As for servers, some storage units are never used. By profiling storage usage, you can identify duplicate data, old data, unused data and inefficient tiering strategies. With the energy and cost profiles of storage equipment at your fingertips, you can make conscious decisions on consolidation.
4. Asset reconfiguration. Because emphasis on energy is a recent development, most IT equipment is still configured without energy efficiency in mind. For instance, Sentilla has observed savings of 33 percent by reconfiguring fileservers to go in a low-power mode at night and during weekends, and savings of a few percent by changing server power management settings to match workloads. Energy management software can identify the right assets for this operation and determine low-impact changes that net energy utilization improvements.
5. Finally, data center executives can delay capital expenditure. Many data center executives worry about capacity on their Uninterruptible Power Systems (UPSs) and Backup Generator Sets. This type of power equipment requires major capital investments and necessitates significant resources during installation (it most likely involves interruption of IT services). Energy management tools directly follow power demand on the UPS and track capacity. A good tool will continuously monitor capacity on the UPS and give data center executives all the information they need to reclaim stranded power (allocated but not being used).
Joe Polastre is the CTO and co-founder of Sentilla Corporation.