Inside one of the world's largest data centers

CNET gets a tour of Microsoft's 700,000-square-foot Chicago facility--a data center the company says just might be the biggest on the planet.

Ina Fried Former Staff writer, CNET News
During her years at CNET News, Ina Fried changed beats several times, changed genders once, and covered both of the Pirates of Silicon Valley.
Ina Fried
4 min read

CHICAGO--On the outside, Microsoft's massive new data center resembles the other buildings in the industrial area.

Even the inside of the building doesn't look like that much. The ground floor looks like a large indoor parking lot filled with a few parked trailers.

It's what's inside those trailers, though, that is the key to Microsoft's cloud-computing efforts. Each of the shipping containers in the Chicago data center houses anywhere from 1,800 to 2,500 servers, each of which can be serving up e-mail, managing instant messages, or running applications for Microsoft's soon-to-be-launched cloud-based operating system--Windows Azure.

Upstairs, Microsoft has four traditional raised floor server rooms, each roughly 12,000 square feet and consuming, on average, 3 megawatts of power. It's all part of a data center that will eventually occupy 700,000 square feet, making it one of the world's largest.

"I think, I'm not 100 percent sure, but I think this could be the largest data center in the world," said Arne Josefsberg, general manager of infrastructure services for Microsoft's data center operations.

Even with only half the site ready for computers, the center has 30 megawatts of capacity--many times that found in a typical facility.

On a hot day, Microsoft would rely on 7.5 miles worth of chilled water piping to keep things cool, but general manager Kevin Timmons smiled as he walked in for the facility's grand opening in late September. It was around 55 degrees outside.

"When I stepped out, I said 'what good data center weather'," he said. "I knew the chillers were off."

Although Microsoft is open about many of the details of its data centers, there are others it likes to keep quiet, including the site's exact location, the names of its employees, and even which brand of servers fill its racks and containers.

The software maker also won't say exactly which services are running in each facility, but the many Bing posters inside the upstairs server rooms in Chicago offer a pretty good indication of what is going on there.

Microsoft originally intended to open the Chicago facility last year, but the company has slowed its data center pace some amid the weaker economy and an array of cutbacks companywide. Instead, the facility had its grand opening in late September.

Of Sidekick--and Azure
Within a month, though, Microsoft's data centers were attracting attention for a wholly different reason. A massive server failure at an older facility--one that Microsoft acquired as part of its Danger acquisition--left thousands of T-Mobile Sidekick owners without access to their data as part of an outage that is now stretching into its second month.

Although Sidekick uses an entirely different architecture, the failure represented a tangible example of the biggest fear of cloud computing--that one will wake up one day to find their data gone.

Photos: Inside a Microsoft data center

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Microsoft is quick to highlight the differences between the Sidekick setup and what Microsoft is building in Chicago and elsewhere. "We write multiple replicas of user data to multiple devices so that the data is available in a situation where a single or multiple physical nodes may fail," Windows Azure general manager Doug Hauger said in a statement after the Sidekick failure.

As for Azure, Microsoft is expected to talk about its commercial launch at this month's Professional Developers Conference in Los Angeles, including offering more details on how the system will provide its redundancy. Microsoft has already announced some new Azure details, noting last week that it will begin charging for Azure as of February 1.

Microsoft is still trying to figure out just how much capacity at Chicago and elsewhere it needs to assign for Azure.

"Azure is incredibly hard to forecast," said Josefsberg. "We're probably erring toward having a little more capacity than we need in the short term."

What is clear is that, over time, Microsoft will need even more capacity. That's what has Josefsberg returning to a custom "heat map" that figures out the best place to build data centers based on factors including cheapness, greenness, and availability of power, political climate, weather, networking capacity, and other factors. Choosing the right spot is critical, Microsoft executives say, noting that 70 percent of a data center's economics are determined before a company ever breaks ground.

Josefsberg said he already has the next spot picked out.

"We know exactly where it is going to be but I can't tell you right now," he said.

But Microsoft has indicated how the next generation of data center will improve upon the Chicago design.

Moving to containers allows Microsoft to bring in computing capacity as needed, but still requires the company to build the physical building, power and cooling systems well ahead of time. The company's next generation of data center will allow those things to be built in a modular fashion as well.

"The beauty of that is two-fold," Josefsberg said. "We commit less capital upfront and we can then accommodate the latest in technology along the way."