I found this articles in Red Hat Enterprise Linux Introduction to System Administration hand book. I highlight it here for knowledge sharing.
Although the specifics of being a system administrator may change from platform to platform, there are underlying themes that do not. These themes make up the philosophy of system administration.
The themes are:
- Automate everything
- Document everything
- Communicate as much as possible
- Know your resources
- Know your users
- Know your business
- Security cannot be an afterthought
- Plan ahead
- Expect the unexpected
Most system administrators are outnumbered either by their users, their systems, or both. In many cases, automation is the only way to keep up. In general, anything done more than once should be examined as a possible candidate for automation.