The survey, of 157 U.S government IT decision-makers, found that only 25 percent are tracking the amount of storage capacity used at their data centers, and only 26 percent are tracking their data centers' energy consumption. Twenty-three percent of respondents said they can track the savings from data center consolidation, the survey said.

Just 41 percent of respondents said their agencies track the number of servers they operate at data centers, and just 32 percent track their annual storage spending, , released this week by MeriTalk, an online network focused on the government IT community.

The survey raises questions about an OMB plan to close hundreds of government data centers in the next four years in an effort to save money and reduce energy consumption, said Mark Weber, president of the U.S. public sector division at NetApp, a network storage vendor that commissioned the survey. Weber doesn't dispute that there are too many U.S. government data centers, but better tracking would tell OMB which ones should be closed, he said.

"They're really counting physical things, not how efficiently those physical things are utilized," Weber said. "How do you know what to consolidate until you know how efficient it is?"

It would be "common sense" to track data center capacity and energy use before moving forward with OMB's data center consolidation proposal, Weber said.