In 2005, problems in the data center at Pacific Northwest National Laboratory came to a head.

Unscheduled outages were occurring almost monthly, bringing down the data center for hours at a time. Groups were buying an increasing number of rack-mounted servers — which had recently become cheaper at the time — to boost the computing resources, says Ralph Wescott, data center services manager for the government laboratory, which is managed by the U.S. Department of Energy. In July, 2005, the server room had reached its capacity limit.

"Groups would go buy a server and throw it over the wall to me, saying, 'Hey, install this,'" Wescott says. "But I didn't have any space, power or cooling (capacity) left. If I installed (one more), the whole room would go dark."

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Wescott and PNNL embarked on a broad project to revamp their data center without breaking the budget. Every quarter for three years, the data center group spent a weekend shutting down the server room and replacing a row of old servers and tangled network cables under the floor with more efficient, yet more powerful servers connected by fewer cables running in the ceiling. The new configuration allowed for more efficient cooling under the floor.

The result? PNNL moved from 500 applications on 500 servers to 800 applications running on 150 servers.

During a tight economy, tackling such information-technology projects require a tight grip on the purse strings, says Joseph Pucciarelli, the program director of technology, financial and executive strategies for analyst firm IDC, a sister company to CIO.com.

"The situation is a very common one," he says. "Companies are making just-in-time investments. They have a problem, and they are looking at the problem in a constrained way."

Here are some lessons PNNL learned in bringing their data center back from the brink.

1. Plan, don't react

"We decided what the data center should look like and what its capacity should be," he says.

The group concluded that the current trajectory would result in 3,000 applications, each running on its own server, in 10 years. Now, the data center has 81 percent of applications virtualized — and average of 17 per server — and Wescott plans to reach the 90 percent mark.