Logs and Journals

Part of the Linux course

A service that was working yesterday is not working now. Nobody changed anything, or so everybody says. You can stare at configuration files for an hour, or you can go and read what the machine wrote down while it was going wrong. Linux records an enormous amount about itself, and the difference between an operator who fixes things in five minutes and one who guesses for an afternoon is almost entirely knowing where...

Think of logs as an aircraft's flight recorder. Nobody reads it while the plane is flying normally. It exists so that when something goes wrong, there is a minute-by-minute account of what the machine was doing and what it thought about it. Your job is not to read everything, it is to find the thirty seconds that matter.