The Risks and Rewards of Warmer Data Centers

1sockchuck writes "The risks and rewards of raising the temperature in the data center were debated last week in several new studies based on real-world testing in Silicon Valley facilities. The verdict: companies can indeed save big money on power costs by running warmer. Cisco Systems expects to save $2 million a year by raising the temperature in its San Jose research labs. But nudge the thermostat too high, and the energy savings can evaporate in a flurry of server fan activity. The new studies added some practical guidance on a trend that has become a hot topic as companies focus on rising power bills in the data center."

Comments

Risk of AC failure

[Skapare]

If there is a failure of AC ... that is, either Air Conditioning OR Alternating Current, you can see a rapid rise in temperature. With all the systems powered off, the latent heat inside the equipment, which is much higher than the room temperature, emerges and raises the room temperature rapidly. And if the equipment is still powered (via UPS when the power fails), the rise is much faster.

In a large data center I once worked at, with 8 mainframes and 1800 servers, power to the entire building failed after several ups and downs in the first minute. The power company was able to tell us within 20 minutes that it looked like a "several hours" outage. We didn't have the UPS capacity for that long, so we started a massive shutdown. Fortunately it was all automated and the last servers finished their current jobs and powered off in another 20 minutes. In that 40 minutes, the server room, normally kept around 17C, was up to a whopping 33C. And even with everything powered off, it peaked at 38C after another 20 minutes. If it weren't so dark in there I think some people would have been starting a sauna.

We had about 40 hard drive failures and 12 power supply failures coming back up that evening. And one of the mainframes had some issues.