Comment by dumbfounder

This is a secondhand anecdote, but it’s pretty funny. Back in the days of server rooms, a friend’s server for his company would reboot every day around 5pm. They checked everything they possibly could with the OS, they would be logged in and running checks on it and it would spontaneously go offline for about 5 minutes and reboot every day. Finally they decided to go stand in the presence of the server around the time it goes down every day. They watched a cleaner come into the room, unplug the server rack, plug in their vacuum and vacuum around the servers, and then plug the server rack back in.