One of the problems with IT people is that they are rarely well versed in the systems that keep their stuff running.

It is amazing to me how many servers are plugged into a UPS bought at Radio Shack that is in turn plugged into the wall outlet.

generators that run on diesel need to have the diesel fuel tested and/or filtered periodically. it may even need to be replaced occasionally.

some data centers don't routinely test the automatic transfer switch that actually switches the power from the utility to their backup generator.

I read once of a case where the data center security system had a UPS backup but when the UPS battery died during a power failure, people were no longer able to get in because the card reader stopped working.