> How often did you test that? Not parent, but here is a single data point. When I was a student, I worked for some sysadmins who managed a small, internal dat

> How often did you test that? Not parent, but here is a single data point. When I was a student, I worked for some sysadmins who managed a small, internal data center. ~200 IBM servers, a SAN, an old VAX, etc. It had a backup gas generator that was tested loudly, every single week. It was also tested whenever the power went out for too long. Obviously lots can go wrong, even with the best plans, but at least at the tiny little place I worked, the generator was tested every week.