Reduce. It's the first, and arguably the most important, of the "Three Rs" of environmental ethics: Reduce, Reuse and Recycle. And when it comes to greening data centers -- that is, lowering the environmental footprint inflicted by powering and maintaining IT assets within a data center --- reducing the number of IT assets you purchase and maintain will certainly make the other two Rs, reusing and recycling, less of a burden. So how do you start? With virtualization software.
By abstracting physical IT assets into software, virtualization allows the consolidation of servers, thereby reducing energy costs associated with powering and cooling machines by as much as 80 percent.
Virtualization software can be used on mainframes or servers. It can also be used to manage a large number of desktop or laptop computers that are linked into a network. But we'll focus here on the virtualization of x86 servers, which is where most CIOs are focusing as well. By mid-2007, 37 percent of enterprises in North America and Europe adopted virtualization for their x86 server populations, and another 28 percent are planning to do so by 2009, according to research firm Forrester.
Why the sudden interest? In recent years, many firms' data centers have mushroomed to accommodate a sharp rise in computing demand. And as rows of server racks starting multiplying, the energy costs associated with operating them increased in lock step. In dense urban areas, data center managers started facing limitations both in space to house their servers but also in the amount of energy their utility providers allowed them to pull from the grid. These changes pushed data center energy-savings projects way up on many an IT manager's to-do list. And because most applications running on dedicated servers do not require all of the computing powering that each server offers, it's logical to consolidate multiple applications onto single servers.
"We see a lot of companies reach the physical constraints of the data center. They just run out of space. Building a new center is incredibly expensive, so virtualization is a cheaper path," says Joshua Leslie, director of alliances for VMware. The largest and oldest vendor of virtualization software,
VMWare grew the market for virtualization software, but
Microsoft and
XenSource (acquired last year by Citrix) and others are vying for their share of the pie, as well.
According to VMWare, most non-virtualized servers and desktops are used during only eight to 15 percent of the time that they are powered on. Yet even when they are idle, most of this hardware consumes 60-90 percent of its normal workload power. Once virtualized, however, a server running multiple applications or operating systems can significantly lower power requirements. The Port of Seattle, for instance, has virtualized 220 servers onto a total of seven physical servers, which pull only 20 percent of the energy that 220 physical machines would,
according to Northwest Energy News.
And British Telecom made a huge change in its carbon footprint. By consolidating 3000 servers, the utility --- whose huge energy demand had been sucking 0.7 percent of all the power generated in Britain --- saved approximately two megawatts of power, or $2.4M in annual energy costs. It also cut its IT hardware in half while increasing data storage utilization to 70 percent, reduced server maintenance costs by 90 percent.
Inspiring stories, for sure. But virtualizing a data center is a sizable project that takes planning. Herewith, some guidelines that will help make the transition smooth and your energy-savings optimal.
Chart a Course to an Optimized Solution
Before getting started, look for ways to reduce or defray the overall cost of the project. First, make sure to run any plans to consolidate your data center up the flag-pole in order to see if there are funds in your company's corporate social responsibility budget or other green initiatives that can be used to support the project.
Also, power companies in many parts of the country offer rebates to companies that reduce consumption through server and storage consolidation efforts, so check with you local utility to find out how to qualify.
Most virtualization vendors offers a free evaluation copy of their software, often good for 30 days. Take the time to run the tests, and while you're doing so, conduct a server audit to gauge the computing demands of various applications. Keep in mind that some apps are often idle but have spikes in activity periodically, in response to demands for reports, inventories, or other business processes. The higher computing demands of the applications, the fewer you'll be able to consolidate. Companies are generally able to consolidate up to 30 different file and print servers onto a single physical server.
Purchase Virtualization-Friendly Hardware
Dell, HP and IBM have started partnering with vendors of virtualization software in order to embed their products onto servers so that they are ready to support multiple operating systems and applications right out of the box.
You might not be ready to purchase new servers now, and that's not something you'll need to do at the same time you install virtualization software -- in fact, Leslie suggests consolidating servers first, which makes it easier to know how many fewer new servers you'll need once you're ready for new ones.
Server makers also offer multi-core processors that feature high RAM and network bandwidth, designed to support virtualization. For a review of two such servers by Dell, and a look how to benchmark the performance of these servers --something you'll want to do given their high price tags relative to standard servers --
check out Andrew Binstock's take.
Synchronized Server and Storage Virtualization
When you consolidate the servers in your data center, "absolutely synchronize server virtualization with storage virtualization," advises Dave Vellante, co-founder and principal contributor of
Wikibon, a website community of IT technologists and consultants who share knowledge and insights into data storage, backup and related topics. You'll already be taking a good look at the applications you're running, so it's a good time to consider your data storage needs and likely rearchitect your data back-up system. This will be especially true if you deploy a function of virtualization software that allows you to automate data backup schedules.
And from an energy point of view, consolidating storage will come down to getting rid of more servers. "For storage," says Vellante, "it's all about eliminating spinning discs."
Coordinate Efforts with Facilities Staff
If the data center managers aren't already in close communication with the facilities managers, they ought to be very soon. The reason: the two staffs need to work in concert to make a data center more efficient. You might go through and happily unplug a good portion of your servers once you consolidate them, but if the building has poor ventilation, you're not doing as much as you can to lower energy costs.
"Working with the facilities department is important, and I would say this happens very seldomly," says Vellante. "The majority of data centers are ill-equipped to handle heat from servers, because many years ago, the IT people probably didn't spec out the heat density of their servers, nor did they anticipate the spike in energy consumption ahead of them."
Calculate the Real Costs
In calculating costs, be sure to look beyond the costs of obtaining and maintaining the virtualization software minus the money you'll save on hardware and energy costs. Many virtualization software vendors offer online total cost of ownership calculators, but use these only for generating a rough idea of costs and benefits and use your own resources or a third-party consultant to get the bottom-line estimate. But be sure to also factor in the operational efficiencies you'll enjoy. Before consolidating its data centers, it would take personnel from the British telecom company one week to set up just one new server. Using its virtualization software to do so now takes one business day. The company can now also do a full daily backup of all its WinTel servers in a half hour. These efficiencies contributed to its massive energy and asset savings, all of which enabled BT realize a return on its investment in virtualization within eight months.
In the end, virtualization is not a panacea to high energy costs. It is only one tool in a quiver that includes better overall utilization and tracking of mobile IT assets, smarter approaches to temperature management inside data centers, and other strategies such eliminating redundant back-ups and using thin-clients to virtualize desktop and laptop computers in your office. But virtualization can be the most effective tool in greening your data center.
