If you’re an IT professional, facility manager, or energy manager and operate a data center, then you know how much energy it takes to keep all your servers running smoothly. You may also be aware of how much money that energy costs your company every month. Fortunately, there are several changes you can make to reduce energy costs while maintaining — and even increasing — your data center’s performance. According to ENERGY STAR, here’s a list of the top five strategies you can implement in your data center to start saving energy and money right away.
1. Server Virtualization
As you may know, a virtual server is a software implementation of a server. It executes programs like a real server does but allows you to run multiple independent “servers” on a single physical server. The idea is that the virtual servers use more of a physical server’s processing power, which means you can run fewer physical servers and cut energy costs.
Estimated Savings: Consolidation ratios between 10:1 and 15:1 can be achieved with today’s servers, resulting in reductions in data center energy expenses from between 10 percent and 40 percent.
2. Decommissioning of Servers
Aged servers with no use that are still running and eating up energy costs, so-called “comatose” servers, are a problem in data centers. Unless you have a rigorous program of decommissioning comatose servers, it’s likely that between 15 percent and 30 percent of the equipment in your data center is comatose, according to Kenneth Brill, executive director of the Uptime Institute. Removing just one comatose server produces a “cascade effect” of energy savings from the server, power distribution unit, UPS, cooling system and building transformers.
Estimated Savings: When Sun Microsystems decommissioned unused servers, for example, the company reported an 8 percent to 10 percent cut in equipment load and an 11 percent to 14 percent decrease in total load.
3. Consolidation of Lightly Utilized Servers
The traditional “one workload, one box” approach to server provisioning in data centers results in an abundance of underutilized servers. Since typical server utilization is about 5 percent to 15 percent, most servers run at or below 20 percent utilization most of the time, but still require full power to operate. To solve this problem, combine multiple applications onto a single server and a singe OS instance, cluster servers to reduce the number of backup or standby servers, downsize the application portfolio to eliminate redundant applications and virtualize servers whenever you can.
Estimated Savings: Given that the average U.S. server’s energy cost is about $820 per year, according to Stanford University, the potential for savings is significant.
4. Better Management of Data Storage
Hard disk drives and media that retain digital computer data can use a lot of energy. According to some experts, however, “white space,” or the amount of storage that goes unused, averages about 70 percent per device. And, of the 30 percent that is utilized, some of that can be attributed to duplicate data. You can better utilize your data storage by deploying storage resource management (SRM) tools, automating storage provisioning and deploying thin provisioning, organizing storage by tiers, installing a massive array of idle disks (MAID) for tier 3 storage and considering the advantages of solid state storage, which has no spinning disk to power.
Estimated Savings: Better data storage management can lead to significant energy savings; MAID solutions alone can reduce energy costs associated with data storage by 60 percent or more.
5. Purchasing More Energy-Efficient Servers, UPSs and PDUs
One of the most direct ways to increase the energy-efficiency of your data center going forward is to simply start purchasing more energy-efficient technology, including servers, UPSs and PDUs. The latest OSs can also play a role. Windows Server 2008 R2, for example, includes a number of efficacy improvements. It continually alters the power states of server processors in response to utilization workloads and includes features such as Core Parking, Time Coalescing and Intelligent Timer Tick Distribution, or Tick Skipping, which helps keep processor cores in deep sleep when they’re not needed.
Estimated Savings: New servers are typically about 30 percent more efficient than older servers (while being able to perform three times the workload at 50 percent utilization). New, energy efficient UPSs typically hit efficiency rates from 92 percent to 95 percent. New PDUs are about 2 percent to 3 percent more efficient.
6. Hot Aisle/Cold Aisle Layout
Many data centers logically place their server racks in neat rows from front to back, with server cold air intakes at the front and hot air exhausts at the back. While this may seem like a logical way to arrange your racks, it means as the server racks go back, they begin to take in warmer air, which can result in higher fan speeds to keep the servers in the back rows at ideal operating temperatures. A better solution is to implement the hot aisle/cold aisle layout, which mandates that server racks are arranged so that cool air intakes face each other and warm air exhausts face each other. That way, you ensure that your cool air intakes are constantly receiving cool air.
Estimated Savings: According to the U.S. Department of Energy, when used in combination with appropriate containment, a hot aisle/cold aisle layout scheme can reduce fan energy use from 20 percent to 25 percent.
Do you agree or disagree with ENERGY STAR’s recommendations? Have you implemented these or other energy-saving strategies in your data center? Leave us a comment below and let us know how they’re working.
ENERGY STAR, “Data Center Energy Efficiency Strategies.”