Last night Facebook’s Open Compute Project posted a post-mortem on the project’s blog, detailing how the the airside economization and evaporative cooling system had malfunctioned, resulting in numerous server reboots and some shut downs due to power supply unit failure. A problem in the control system resulted in the evaporative cooling system spraying 100 percent of the time to increase the humidity, leading to condensation on the servers and failures. It’s good to see Facebook be so open about the issue and the measures it has taken to correct it. This will help everyone build better, more energy efficient data centers.