Government Computer News
The means to go green
COVER STORY: How to eke out energy savings in servers, processors, networks and storage systems
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TechnoratiEditor's note: This report is part of a broader 360-degree joint reporting effort by Government Computer News, Federal Computer Week, Washington Technology and the 1105 Government Information Group. GCN covers the technology developments propelling green IT, FCW focuses on the policy and management aspects of green IT and Washington Technology looks at its effect on contractors and suppliers. The full collection of stories are available here.
Want to make your data center more environmentally friendly? Or just cut the power bills for your agency? The path to either goal is the same: Greater energy efficiency.
With the general public becoming more aware of energy efficiency and with the cost of the kilowatt hour creeping up, the government data center certainly could stand to sharpen its energy usage profile.
For one thing, President Bush has mandated reductions in energy usage. In January, the White House issued an executive order calling for each agency to improve energy efficiency and reduce greenhouse gas emissions either by 3 percent annually through the end of fiscal year 2015 or 30 percent by the end of fiscal 2015, depending on its current energy use profile (GCN.com, Quickfind 872).
Data centers would be a good place to start. They can be as much as 40 times more energy-intensive as conventional office buildings, according to a study by Lawrence Berkeley National Laboratories for the American Council for an Energy-Efficient Economy.
And a lot of that power is consumed by information technology equipment. Server sprawl is taking up precious data center space and consuming a lot of power, resulting in high utility bills.
The combination of memory, disks and network interfaces can exceed the power consumption of a CPU.
Plus, excess hardware capacity can lead to significant energy waste.
The good news is that many technologies commercially available or soon to be available could improve the energy efficiency of data centers.
Advances in virtualization technology allow data centers to pool multiple applications, servers and storage into a single source of shared resources, saving space and power. Multicore processors offer better power management and can handle more workload in parallel than a single-core chip.
Ongoing work in national laboratories and standards bodies will pave the way for more energy-efficient Ethernet networks and other networking equipment.
Meanwhile, storage devices are expected to become more efficient because of a shift to smaller hard drives and increased use of Serial Advanced Technology Attachment drives, according to a report issued to Congress on server and data center energy efficiency by the Environmental Protection Agency and industry stakeholders.
And improved management of storage resources could foster significant data center energy savings.
Here is how manufacturers and researchers are developing ways to boost energy efficiency across all the major data center components, including servers, microprocessors, networking and storage.
Servers: Utilize more, cool better
The underuse of servers is often cited as a reason for sub par energy efficiency in data centers. Efforts to get more out of existing servers could have a significant effect on energy savings in many U.S. data centers and server installations, experts say.
“Servers aren’t fully utilized,” said Joe Wagner, senior vice president and general manager of system resources at Novell. The typical volume server runs at between 15 percent and 30 percent of use, compared with 70 percent to 80 percent on a mainframe system, he said.
Virtualization is one way to pool and share resources to reduce costs and optimize utilization. Users can virtually collapse workloads, Wagner said. For instance, they can merge three single servers, each running at 15 percent capacity, into one server running at 45 percent to 50 percent capacity.
Novell’s SUSE Linux Enterprise Server 10 with built-in Xen open-source virtualization software lets users consolidate Microsoft Windows and Linux workloads onto a single server, Wagner said. This can reduce power, cooling and space requirements.
Although virtualization also adds a new layer of complexity, Novell’s ZENworks Orchestrator and virtual machine management software provides an automated, policy-based solution that can simplify virtualization operations. It can also boost energy efficiency by shutting down machines when they’re not in use in addition to distributing virtual and physical workloads across the data center for maximum efficiency.
Meanwhile, major computer manufacturers are moving toward the production and marketing of more energy-efficient servers.
Several key features are the use of multicore processors with power management and virtualization capabilities, high-efficiency power supplies, and internal variable-speed fans for on-demand cooling, the EPA report to Congress states.
Dell, for example, has incorporated the Energy Smart technology used in its desktop computers into Dell PowerEdge Servers to decrease power consumption and overall operating costs.
Dell PowerEdge Servers also can work with Emerson Network Power’s Liebert XD and DS, two cooling modules that use advances in refrigerants and compressors to improve the energy efficiency of the cooling process.
In developing Energy Smart, Dell took a close look at its own data center to determine which equipment was consuming the most power, said Jon Weisblatt, senior manager of solutions marketing at Dell. “The majority of that was IT equipment.” Sixty percent of the IT power consumption was directly attached to server usage, he said.
EPA’s Energy Star program has focused on data centers by supporting development of energy performance measures for servers.
“Energy efficiency is the cornerstone of what you can do to make things greener,” said Jack Pouchet, director of green initiatives at Emerson Network Power. “Data center managers need to assess where they are today. If not, they have no idea where they are going.”
The Energy Department is working with other industry stakeholders such as the Green Grid consortium to develop assessment tools within the next 18 months.
DOE has assembled the expertise to develop metrics, measurements and tools with the goal of empowering data center decision-makers, said Paul Scheihing, who works at DOE’s Office of Energy Efficiency and Renewable Energy in the Industrial Technology Program.
DOE is interested in an overarching set of tools that will help data centers profile energy use and gather and quantify metrics, he said.
Processors: More cores
The two big commodity chip-makers, Advanced Micro Devices and Intel, have been developing and improving multicore chips. Further energy savings can be attributed to the development of dynamic frequency and voltage scaling in addition to virtualization capabilities, experts said.
Multicore processors contain two or more processing cores on a single die, which run at slower clock speeds and lower voltages than the cores in single-core chips but can handle more work than a single-core chip.
For example, AMD’s Quad Core Opteron processor with Direct Connect Architecture provides fast input/output throughput by directly connecting input/output to the CPU, said Rick Indyke, federal business development manager at AMD.
An integrated memory controller decreases power by removing external memory controller requirements. AMD PowerNow technology with Optimized Power Management dynamically reduces processor power based on workload, giving users power savings of as much as 75 percent, AMD officials said.
The Quad Core Opteron also offers advanced Silicon-on-Insulator technology for faster transistors and reduced power leakage.
AMD Virtualization technology, which is hardware-based, lets virtualization software run multiple operating systems and applications on a single physical AMD Opteron processor-based server.
Earlier this month, Intel launched the new Quad-Core Intel Xeon processors using 45- nanometer technology that offers reduced idle power levels to maximize efficiency. It does this through a combination of 45-nm low-leakage and system-transparent energy smart technology.
A reduction in a processor’s idle power usage helps to lower average server power consumption over time during normal server operation, said Nigel Ballard, government marketing manager at Intel.
IntelVT FlexPriority, a new VT extension available in the latest Intel Xeon processors, optimizes virtualization software by improving interrupt handling. Intel claims it can boost virtualization performance by as much as 35 percent for 32-bit guests.
Networking: Only what you need
Servers are not the only components in the data center that draw power. Three efforts are under way at the Lawrence Berkeley National Laboratory (LBNL) to make Ethernet networks more energy efficient.
Adaptive Link Rate technology, or Energy Efficient Ethernet, focuses on letting Ethernet data links adjust their speed — and power — to traffic levels, said Bruce Nordman, a researcher in the lab’s Environmental Energy Technologies Department.
Ethernet links do not vary the rate at which data is transmitted even if little data is moving along the link. Higher data rates require a lot of power, so more energy is being used to transmit small amounts of data, LBNL researchers said.
Some computers can change the speed of a link when they are in sleep mode or turned off, but the process is too slow when they are idle or active.
So the solution is to change the network link speeds quickly in response to the amount of data being transmitted.
LBNL is working with the Ethernet Alliance and the Institute of Electrical and Electronics Engineers’ 802 standards committee to develop Adaptive Link Rate into a standard, said Mike Bennett, an LBNL researcher and chairman of the IEEE Energy Efficient Ethernet Task Force.
Another project aims to develop proxying specifications that would let PCs and other devices sleep while other equipment maintains their network presence.
There are many reasons users might need to stay connected to a network while they are not at their desktops. “I hear of a lot of government agencies where you need to leave your machine on at night to [receive] updates such as security patches,” Nordman said. If the desktop PCs are allowed to stay in sleep mode but still are accessible, data centers could save millions of dollars on energy a year, he added.
A proxy can provide a solution, he said. There are three ways to implement proxy, according to a white paper written by Nordman and University of South Florida Professor Ken Christensen:
- Self-proxying puts the functionality within hardware, such as a network interface card. “The key is to not require the power-intensive main processor, memory and most buses to be active during sleep,” the paper states.
- Switch proxying puts the functionality into the immediately adjacent network switch so that the end device doesn’t have to be changed. Other devices on the network are not aware the end device is asleep.
- Third-party proxying puts the functionality somewhere in the network other than the device or adjacent switch.
The third project LBNL is working on would establish energy efficiency specifications to help manufacturers develop and users buy network equipment that consumes less electricity.
Storage: Get smart
A lot of energy-saving effort understandably goes to hardware. But for some observers, green IT begins with green data.
The ever-increasing volume of data in storage systems could make these devices the top power hogs in the data center, said Jon Toigo, chairman at the Data Management Institute and founder of the Green Data Project. He noted that research firm IDC projects a 300 percent increase in storage devices purchased between 2006 and 2010.
But there are technology and management strategies for saving power on storage — such as storage virtualization, data deduplication, storage tiering and moving archival data to storage devices that can be shut down when not in use — said Sateesh Narahari, senior manager of marketing at Symantec. The company offers a handful of products to manage and use storage more efficiently, such as Symantec NetBackup, Symantec Veritas Cluster Server and Symantec Veritas CommandCentral Storage.
Still, Toigo questions whether efforts such as data deduplication and storage tiering — all good initiatives — are more tactical than strategic.
A strategic approach requires knowing what’s on your server drives, he said.
Typically, about 40 percent of the data is inert; 30 percent is well used; 15 percent is allocated but unused; and 10 percent is orphaned, meaning the owners of the data are no longer with the organization; and 5 percent is inappropriate, Toigo said. The figures come from a study he conducted with Randy Chalfant, Sun Microsystems’ chief technology officer.
Data center managers need to employ intelligent archiving, which gives users more specific information about the content and context of data stored on systems. Then they must deploy storage resource management technology that has thin provisioning functions so they can reclaim unallocated space, Toigo said.
Archiving selectively and intelligently is the strategic approach, he said.
“Intelligent archiving, storage resource management and data hygiene will bring in a lot greener environment than anything on the hardware level,” Toigo said.
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