[MoosePirate]

> In the event of a power outage, one provider could only give us 30 seconds of emergency power—versus five minutes with a standard UPS setup—because they used an inertia wheel.

If a generator fails to start in 30 seconds, that almost always means it will also not start within 5 minutes.

Does dropbox have automation that attempts to gracefully shut down systems if a generator fails to start? Are systems then kept down until the battery UPS system is fully recharged? If not, the difference between 30 seconds and 5 minutes doesn’t seem important.

[ramraj07]

Our Indian Condo complex generator regularly takes more than 30 seconds to start up. Even the best case is likely at 10 seconds so only having such a small cushion sounds dangerous.

[slyall]

Possibly not. AWS had an outage in Sydney in 2016 where the longer interval available with a battery UPS might have avoided the problem.

https://aws.amazon.com/message/4372T8/

[rainbowzootsuit]

Some rough calculations on a fully loaded data center that I have worked on designing shows that you only have about a minute before the air gets to an overheating condition due to the low heat capacity. The HVAC doesn't keep running through a total power failure even if the computers have a lot of reserve power.