10.1. Maintaining the System

Being the system administrator for any Unix system requires a certain degree of responsibility and care. This is equally true for Linux, even if you're the only user on your system.

Many of the system administrator's tasks are done by logging into the root account. This account has special properties on Unix systems; specifically, the usual file permissions and other security mechanisms simply don't apply to root. That is, root can access and modify any file on the system, no matter to whom it belongs. Whereas normal users can't damage the system (say, by corrupting filesystems or touching other users' files), root has no such restrictions.