This story has been updated.
The White House plans to close 40 percent of roughly 3,100 federal data centers by 2015,according to a new blog post by federal Chief Information Officer Steven VanRoekel.
That amounts to shuttering about 1,200 centers. The government expects to save $5 billion overall through the consolidation, according to earlier estimates, but VanRoekel hasn't given a firm end date for when those savings will be realized.
Agencies have committed to shuttering 1,080 data centers so far, VanRoekel said. The remaining 120 or more centers will be identified in the future, a spokeswoman said.
The total number of data centers the government planned to shutter was thrown into question in October when the CIO announced he was expanding the definition of a federal data center to include small government-owned data rooms and closets scattered across the country.
The White House had earlier announced plans to shutter about 800 of 2,100 federal data centers by 2015. That plan, established by VanRoekel's predecessor Vivek Kundra, included only facilities that measured at least 500 square feet.
In an October conference calls with reporters, VanRoekel estimated government's data center footprint under the expanded definition would be about 2,800. The new figure of 3,133 data centers is the result of a governmentwide inventory since October, a VanRoekel spokeswoman said Wednesday.
The consolidation goal will remain at roughly 40 percent of the government's data center inventory regardless of any new information on the number of facilities, she said. It's not clear whether VanRoekel's office still intends to shutter 40 percent of data centers that exceed the original 500-square-feet definition.
The consolidation program also is aimed at revamping many remaining data centers to take advantage of new virtualization technology that allows federal agencies to store information more efficiently and cheaply. The government also aims to save roughly $5 billion annually by 2015 by transitioning to more nimble cloud computing storage.