First came data centers with no chillers. But is the industry ready for a data center with no UPS and no generators?
That seems like a radical concept. But Yahoo is considering going without UPS (uninterruptible power supply) and generators for some future data center projects. It's not alone in advocating design choices that represent a huge departure from current practice. A number of data center designers are urging clients to consider limiting UPS support to loads that are genuinely critical.
Scott Noteboom, the head of data center operations at Yahoo, said in his keynote at last month's 7x24 Exchange conference that the Internet portal is exploring scenarios in which it would build data centers without generators or UPS, and use its network to route around any power outages that occur at those facilities.
That’s a strategy that only the largest data center providers can contemplate, as it requires multiple data centers in major network capacity. Google has pursued a similar strategy during maintenance on some of its data centers, shifting capacity to other facilities (see How Google Routes Around Outages for details).
Chillers Targeted for Elimination
Google, Microsoft and Yahoo have all built new data centers that operate without chillers, eliminating one of the most power-intensive pieces of equipment from their infrastructure. This has been accomplished by building new facilities in locations that support fresh air cooling. Eliminating key components in power infrastructure is a tougher challenge, given the data center industry's focus on redundancy and reliability.
Noteboom says the Yahoo team is exploring a design in which only a small portion of a data center would have UPS support, primarily for the task of managing a transition in the event of an outage. He says it's the next step in Yahoo’s ongoing effort to improve efficiency and drive down costs in its data center operations. The company has progressively examined aspects of its data center operations, challenging long-held assumptions about temperature and humidity and focusing on free cooling.
Yahoo's not alone. The recently-completed National Petascale Computing Facility (NPCF) at the University of Illinois, which will house the Blue Waters supercomputer, will also operate without a UPS and generator. The decision was based on the "a hard look at the historical performance and uptime" of the university's Abbot power plant.
Scientists will use Blue Waters for research that will predict the behavior of complex biological systems, design new materials at the atomic level, and predict the behavior of hurricanes and tornadoes. While these are important tasks, there would be minimal public impact if work was interrupted briefly in a scenario where the facility loses power.
Defining What Systems Are Essential
Data center designer KC Mares of Megawatt Consulting says he urges customers to take a hard look at which IT functions are truly "always on" essential, and which systems can afford interruptions.
"Once we dive into the operations, we always come back with an answer from the data center operators that only a portion of the computer load needs to be on UPS, and the rest can go down during a usually irregular utility outage," Mares wrote in a recent blog post on the topic. "The reason is that these computers can stop operating for a few hours and not affect the business."