CIOIN

Inside a green datacenter

In datacenter life, that "forever" translates to a good 20 to 30 years -- at least for this New York-based global financial giant.

"We've succeeded in developing a very flexible platform that can adapt easily and seamlessly to changes in customer technologies and allow for differences in heat densities, power consumption and physical layout without causing severe interruptions to their service requirements," Carney says.

Jack Glass, executive vice president of critical systems engineering, says he likes to tell Citi clients this about the company's new datacenters: "We can do anything anywhere but we can't do anything everywhere."

If a Citi business unit wants blade servers here and a grid there, the company's modern datacenter infrastructure can handle each request, Glass says. "That's how flexible it is. We can allocate that capacity and have high-density areas and low-density areas -- our hands aren't tied in the datacenter space," he adds.

Global view

That wasn't always the case. Five years ago, Citi faced a number of challenges relative to its aging datacenter infrastructure. Capacity was exhausted, flexibility limited and "proximity risk" too high because, at the time, Citi had concentrated most of its processing in major metropolitan hubs such as London and New York.

Out of those challenges arose a cohesive, global datacenter strategy.

"What we had been doing was incremental and now it was time to take a big step," Glass says.

The plan calls for Citi to reduce the number of datacenters worldwide from 52 to 14 strategic sites, including five constructed from the ground up. The latest of its new North American datacenters, in Georgetown, Texas, went online in January.

Citi, not unlike many companies, faced an interesting dilemma as it undertook this global datacenter strategy. While it certainly upgraded datacenters here and there and expanded others, it hadn't built a completely new one in North America in 20 or so years, Glass says. In Europe, Citi last built a brand-new datacenter 10 years ago.

But it quickly learned a few essentials, and the Georgetown datacenter represents the culmination of all the lessons, Carney says.

No. 1, the datacenter team realized it needed a global standard for datacenter construction and engineering. "We're not dictating to the Nth degree all of the components but putting in place criteria for reliability, maintainability and redundancy," he says.

And two, teamwork matters. Carney's datacenter team provided the engineering perspective and the corporate real-estate representatives lent the construction expertise to the projects, he says. "We brought together the same team throughout the strategy ... so we could build upon each project and apply the best practices and lessons learned as we went along."

"With Georgetown being the last of major construction projects we did it's where we're really running on all cylinders," Carney says.

LEEDing the way

The effort paid off. Citi's Georgetown facility is the first newly constructed datacenter to receive Leadership in Energy and Environmental Design (LEED) Gold certification from the U.S. Green Building Council (USGBC).

And it did so with little modification to the original datacenter plans, which predated the current overall business emphasis on green and LEED certification, Glass says. "Certification pays for itself in some period of time and it plays right into Citigroup's corporate commitment to reduce its carbon footprint," he adds.

Citigroup worked with HP Critical Facilities Services, delivered by EYP MCF,  to design the LEED-certified datacenter. In an unofficial review, the HP services team says it believes Georgetown also will meet USGBC's impending datacenter certification requirements, Glass says.

In the 100,000-square-feet of raised floor in the Georgetown datacenter, Citi delivers 75 watts per square foot of power, expandable to 100W/square foot. Citi has divided the datacenter into four equally sized rooms. This setup reduces the amount of cabling needed and allows Citi to group technologies by room based on cooling requirements.

Compared with the previous newly constructed datacenter, the Georgetown site uses 800 kilowatts less power for the same footprint, for a 30 percent reduction in energy costs, the company reports.

The Georgetown center primarily supports 'Citi's consumer businesses. The branch operation comprises a mainframe infrastructure, an extensive storage network and a tape backup environment, Carney says.

The datacenter also houses a large number of Unix servers hosting human resources, purchasing and other major corporate applications. Other applications run on a distributed Wintel server environment, he adds.

After much planning and many dress rehearsals, Citi began moving the branch operation to the Georgetown datacenter "critical application by critical application." It wrapped up the migration in August, and closed the corresponding, outdated, New York datacenter at the end of September.

Yardstick for virtualization
Thanks to virtualization, the IT infrastructure is much streamlined compared with legacy centers. Citi uses a 30 percent to 35 percent reduction in the number of physical servers as the yardstick for its new datacenters, Carney says.

"Last year," he adds, "was the first time that we didn't experience any growth in our physical server category because of the amount of reduction we've done on tech refreshes through virtualization."

Glass elaborates: "We have more than 4,000 server virtual instances, and that number replaces many times the number of physical servers. That means anywhere from 12,000 to 20,000 servers weren't installed or were converted to virtual servers."

Virtualization also has bent the curve on power consumption for technology on the datacenter floor, Carney says. In the 2002 to 2007 timeframe, Citi's datacenter power consumption grew by 10 percent to 12 percent per year, he says.

"Last year, as virtualization kicked in and we've gone through legacy datacenter closures, for the first time we've been flat on power consumption year over year."