Virtualization Enables Data Centers to Pull the Plug on Skyrocketing Power and Cooling Costs

The specter of a power crisis is stalking data centers from North America, to Western Europe, to the Far East. Once an after-thought to the cost of running a state-of-the-art data center, electricity costs today represent the fastest rising cost category in data centers. While capital spending on servers in data centers has slowed, businesses are watching their operating costs soar. At the top of the list of rising operating costs sits electricity. For each dollar businesses spend today on additional servers, they are spending another 57 cents to power and cool them, according to IDC consulting firm (link resides outside of ibm.com). That spending on power and cooling is more than double the comparable level of spending just five years ago, says IDC.

If data center managers are looking for a culprit to blame for their rising energy costs, they need only look in the mirror. Server customers historically have demanded increased computing power, internal memory, and disk drives to handle increasingly complex applications and growing workloads as online business and other data processing needs expand. While greater computing and storage power have enabled businesses to become more efficient and process the torrent of data flooding the data centers, it also has increased energy consumption and the related heat load. According to IDC, the typical server today draws four times the power of a server ten years ago. In addition, today's smaller servers enable data center managers to increase the density of servers in these centers by an average of 15% a year. Not only are today's servers placing greater thermal loads on power and cooling systems, but there are more of them packed into the same space with the same cooling system. This has created hotspots in data centers and can trigger outages and reliability issues.

Compounding the power conundrum is the fact that many data centers don't even have the option currently to simply upgrade their cooling capabilities and pay for additional power. About 40% of data center customers say their local utility lacks the distribution to meet their power needs in the near term.

Solutions for Today and Tomorrow
Not surprisingly, pressure is mounting on IT managers to come up with quick fixes to the challenge of demands for greater computing and storage capacity, rising costs, and limited supply of additional power.

While there are a host of long-term steps that businesses can take to rein in power costs, many businesses are taking a multi-step approach to this problem. The first step usually is around assessment and understanding exactly how energy efficient or inefficient their data center is today. They may look at new ways to use cabling under the raised floor to improve the air flow through the data center, or at switching from air to water to cool their data center.

One of the easiest first steps to take is to implement more energy-efficient technologies that are available right now like virtualization. Virtualization allows you to aggressively and actively manage the power consumption within data centers.

At first, it may sound odd that adoption of virtualization can yield significant savings in power and cooling costs. However, virtualization is achieving just that for numerous IBM customers. Take Pacific Gas & Electric. The big utility consolidated 300 Unix servers into six bigger Unix servers using IBM Virtualization. The consolidation drove up capacity utilization of servers to 75% from 10% and yielded an 80% savings on power costs. Similarly, Hannaford stores replaced hundreds of PC servers with two small mainframes running Linux. That step saved 80% on power costs and enabled the company to reduce its staff devoted to server maintenance significantly.

This shouldn't be surprising. After all, the most efficient server is the server that is powered down, and that's precisely what IBM Virtualization does in managing data centers for simplicity, flexibility, and efficiency. Anyone familiar with virtualization may recall that the average peak utilization rate for x86 servers is 10% to 12% and for Unix servers the comparable utilization factor is 15% to 20%. That means for most of the day these servers are consuming power and throwing off heat but are not processing workloads.

"Virtualization enables data centers to retain a high level of reliability and scalability and still meet service level agreements. Running multiple virtual machines on a single physical server boosts server utilization, reducing capital and operating costs."

What IBM Virtualization does is to balance workloads dynamically so that workloads are consolidated using virtual machines into the most efficient configuration on physical machines. This enables servers required to handle peak periods of demand to be powered down during the off-peak hours. Virtualization also reduces power needs by postponing the day when new servers must be purchased to handle the increased workload.

Virtual Infrastructures Create Real Efficiencies
Virtualization acts as an antidote to the server sprawl that has engulfed data centers. Originally, businesses dedicated single workloads to a single server because it provided reliability, availability, and scalability. While this approach did enhance service levels and allow for easier management of workloads by avoiding competition for server resources, it left rack-mounted servers woefully underutilized. Not only were such servers running idle much of the time, but they were consuming power and adding to overhead costs. Virtualization enables data centers to retain a high level of reliability and scalability and still meet service level agreements. Running multiple virtual machines on a single physical server boosts server utilization, reducing capital and operating costs. Moreover, the same efficiencies that can be achieved with server virtualization are also possible with storage virtualization

In fact, virtualization is one of the energy-savings steps that the Green Grid recommends in its recently published Guidelines for Energy Efficient Datacenters : "Virtualization consolidates existing and expected future workloads. This reduces the number of physical servers required, thereby reducing floor space, cooling, and capital costs. It also increases the utilization of servers to improve energy efficiency. Furthermore, virtualization can also serve as an effective means for placing additional compute capability into production." (The Green Grid is a non-profit trade organization of IT professionals formed to address power and cooling issues in data centers. IBM belongs to The Green Grid.)

To be sure, the industry is pursuing some promising new technologies, such as air-gap technology, to reduce power leakage in semiconductors and put data centers on low-wattage diets. However, those promising developments remain years away from the marketplace. In the meantime, businesses need to reexamine their data centers in light of energy needs and costs and right-size the physical infrastructure to accommodate the data processing load, install efficient infrastructure, and design energy-saving systems.

Short-term, businesses must use the proven tools at hand to manage their power costs effectively. Over time, IBM Virtualization has demonstrated how businesses can implement it not only to reduce complexity and consolidate resources but also to reduce power and cooling costs.