A peek inside the N.C. data center where your old Facebook photos go to ‘sleep’ | Charlotte Observer

Those photos of your sweetheart or grandkids uploaded to Facebook live near Forest City along a dimly lit corridor with flashing lights and a constant hum.

The Facebook data center off U.S. 74 has begun an innovative way of looking after those images.

On Wednesday, the 2-year-old data center about 75 miles west of Charlotte hosted a rare media tour that included a new “cold storage” facility that officials say has revolutionized the way Facebook manages billions of photos shared by users.

“It’s a digital attic,” said Keven McCammon. “And it’s designed for growth. The massiveness of storage and data is constantly increasing.”

According to Facebook officials, 350 million new photos are uploaded by users every day. To date, more than 400 billion photos have been shared, requiring a tremendous amount of server capacity and energy.

However, Facebook says 82 percent of its photo-related traffic is focused on just 8 percent of the photos.

With hundreds of billions of photos seldom being viewed, the Menlo Park, Calif.-based social-networking giant came up with a more efficient way to manage the images.

Older photos that aren’t in heavy rotation go into “cold storage,” which refers not to the temperature but the fact that the servers are asleep and not drawing on power. Facebook says the system saves considerable amounts of energy.

Environmentalists have been pressing data centers to cut power consumption. The New York Times reported in 2011 that Google’s data centers sucked in almost 260 million watts, or about a quarter of the output of a nuclear power plant.

Construction on one data hall in Facebook’s cold storage facility has been completed and two more will be ready by June for a total of 90,000 square feet of storage space, McCammon said.

Users can still access the older photos, but it would take only a fraction of a second longer. Users might not notice a difference, he said.

Efficiency was a recurring theme during Wednesday’s tour of the 160-acre campus.

The Rutherford County site overlooking the South Mountains was formerly home to a Burlington textile plant and later a boat manufacturer.

McCammon said the original building was torn down and materials recycled. The data center opened in 2012 in a 350,000-square-foot building, and construction began immediately on another the same size.

Facebook’s Forest City data center is part of a growing N.C. data hub that includes centers for Google in Lenoir and Apple in the Catawba County town of Maiden.

Serving Facebook users in the Eastern U.S. and Europe, the Forest City center has 80 full-time employees.

Michael Kirkland, Facebook’s director of technology communications, said the company was already one of the most efficient but continues to find ways to get better.

One of the center’s unique features is the way outside air is drawn in, filtered and chilled to keep the servers cool.

Efficiencies like this and cold storage facilities have saved $1.2 billion for Facebook over three years.