95 (or so) Theses About System Administration

1. A bored system administrator is a good system administrator.

2. You can't do everything.

3. You can't know everything.

4. The more you customize your system, the more you have to maintain.

   If you make local changes to the OS source, you'll have to reinstall them for each subsequent upgrade.

5. If you install a package, you have to maintain it.

   If you make local modifications to a package, you'll need to make those modifications for each upgrade.

6. Keep it simple

   It is not enough that your setup be simple enough that you can understand it. It needs to be simple enough that your coworkers can understand it when it breaks at 3:00 a.m. and they have to fix it.

7. If you're indispensable, you can't go on vacation.

8. Vendors occasionally have a clue. More often than you think, even.

9. Things will break.

   Bugs will appear. You will make mistakes. You, as a sysadmin, will cause more damage in the long run than break-ins will. Get used to it. Plan for it.

10. RTFM.

    Every so often, take the time to reread the man page for some utility you think you're familiar with, such as grep or find. You'll be amazed at how often you'll learn something new.

11. Trust the user on matters of opinion; distrust him on matters of fact.

    If he says that Notepad is better than Emacs, that settles that issue. If he says that the sky is blue, look outside and check.

    (Thanks to Elizabeth Zwicky for this one.)

12. It's much easier to install than to uninstall.

    If you decide to drop support for Emacs, you'll find that three people depend on it for their Ph.D. research. If you reorganize your web server, you'll find a dozen URLs that can't be changed because they've been published in books.

13. Convince the users; don't force them.

    You can set up all sorts of security, but if it's too hard to follow them, the users won't. If you set up fascist rules on the firewall, users will bring in modems from home, so you'll have a security hole but won't even know about it.

    You might enforce draconian rules about passwords that look like line noise and have to be changed every week. This will lead to people writing their passwords on slips of paper, which can be worse than moderately-bad passwords.