The Hippocratic Oath, taken by doctors, is often paraphrased as “first, do no harm”. I’d like to note the broad applicability of the Hippocratic Oath to system administration. What, for example, is the first thing that you do when receiving a Severity 1 incident in the middle of the night? Correct answer: Look around at your surroundings but don’t change a bloody thing. No good has ever come to a system administrator whose first response is to pound the keyboard furiously and poke around systems, making random changes. This isn’t Hackers, after all. Like a doctor, you need a hypothesis as to what is wrong before operating on your patient.
Beyond just incident handling, though, I’d like to apply the Hippocratic Oath for System Administration using a philosophy that I call, somewhat uncreatively, leaving the defaults the hell alone. Too often I’ve seen people randomly change configuration settings without a true understanding of why. This behavior applies not only to system administrators randomly tuning Linux kernel parameters or PostgreSQL postgresql.conf settings without rhyme or reason. It also applies to the way in which applications are set up in the first place. In this post, I’ll give you some of my guiding principles for leaving things alone and just accepting the defaults even if you know they might not be optimal. In other words, leave the unnecessary tuning for your car, not your job. Continue reading
