The debut of the Sun Modular Datacenter (nee Project Blackbox), a complete data center housed within a shipping container, is an important reminder that data centers can grow greener as they expand.The ability to do both is difficult. Data centers often find they can't expand or they must over-expand, buying more space and more cooling equipment than their computing systems demand. The modular approach can help.

The data-center-in-a-box concept isn't new. As noted by InformationWeek in October 2007, IBM, Google, Microsoft, Rackable Systems, and others offer shipping-container solutions. So, too, apparently is Dell. And it's not for everyone. Sheer weight and security measures notwithstanding, parking a 17,000-pound metal box filled with tons of server racks, and power and cooling equipment isn't for everyone.

But modular expansion is key to data center efficiency. "Scalability in data center design is especially important these days due to ongoing data center space issues that include the ever-expanding need for additional high performance computing and expensive real estate prices in many areas," says John Lamb, senior technical staff member, IBM Global Services, and author of the forthcoming The Greening of IT: How Companies Can Make a Difference for the Environment. "Modular designs and the use of containers are methods of expanding data center infrastructure to provide scalability and at the same time help prevent overbuilding."

The Green Grid, which will be slicing and dicing best practices for data center efficiency at its technical forum next week, makes note of the importance of infrastructure scalability in a 2007 whitepaper:

"Of all of the techniques available to users, right-sizing the physical infrastructure system to the load has the most impact on physical infrastructure electrical consumption. There are fixed losses in the power and cooling systems that are present whether the IT load is present or not, and these losses are proportional to the overall power rating of the system. In installations that have light IT loads, the fixed losses of the physical infrastructure equipment commonly exceeds the IT load. Whenever the physical system is oversized, the fixed losses become a larger percentage of the total electrical bill.

"Right-sizing has the potential to eliminate up to 50% of the electrical bill in real-world installations. The compelling economic advantage of right-sizing is a key reason why the industry is moving toward modular, scalable, physical infrastructure solutions. The very nature of the modular, scalable infrastructure implies that new physical infrastructure equipment is added only when additional IT loads are added."

Sun, meanwhile, has been making hay about its own right-sizing project: a new energy-efficient data center in Broomfield, Colo., that it expects to save $1 million and 11,000 metric tons of greenhouse gases annually. Among other things, Sun consolidated 63 servers and 30 data storage devices into just two Sun servers, the company reports. The data center's modular design has cut its footprint by 66%, says Sun. It is the company's largest retrofit to date. While far from a data center in a box, it did make extensive use its POD architecture, which requires 10% to 15% upfront investment in pipework and floor space to allow the pods to snap into place.

The goal, says Global Lab and Datacenter Design Services senior director Dean Nelson on a Sun promotional video, "was not to save the planet. ... Bottom line: It was to keep our costs under control." The project reduced the data center's square footage to 120,000 square feet from 496,000 square feet.