Power

A UPS without a way to talk to your hosts is just an expensive surge protector with a battery in it. It’ll keep the lights on for a few minutes, but the moment that battery runs out, every VM and container you’re running goes down exactly as hard as it would have without a UPS at all, just a little later. The part that actually protects you, a UPS that tells your hosts “power’s out, shut down now while you still can,” is a separate piece of software most people never get around to setting up. Here’s how to size the UPS itself, and how to wire up Network UPS Tools (NUT) so an outage ends in a clean shutdown instead of a dirty one. ...

Most homelabbers can tell you their NAS’s total raw capacity down to the terabyte and argue at length about CPU generations, but ask what the whole rack costs to run for a month and you’ll get a shrug. That’s understandable, electricity is a background cost that never shows up as a single line item the way a drive purchase does, but a lab that runs 24/7/365 adds up in ways a lot of people never actually check. Here’s how to measure it for real, where the draw actually comes from, and what’s worth changing. ...