This document is a collection of notes and guides for my AIST3720 Operating System Concepts & Administration course at Augusta University.

Some principles of system administration:

  • First, do no harm. If you can't think of 2 or 3 ways to undo what you plan to try next, consider not trying it.
  • Often turning it off and back on again really does work. An exception to this rule might be a malware or virus exploit where a restart can embed the problem further.
  • Read error messages closely. Some can be inscrutable but very often they describe what happened and even suggest what to do. Searching the internet for the exact wording may connect you with a resource where the issue has been resolved.
  • Getting issues to repeat -- not always easy or possible -- is key to getting them resolved; intermittent or sporadic problems are painful, naturally, because when they 'go away' you may not be sure why.
  • Always test re-configurations, in multiple ways if possible. Telling a client, user, colleague or supervisor that something is ready to roll when it isn't is a cardinal sin of system administration.