CentOS, like other Linux and UNIX systems, is intended for use by more than one person at a time. Multiuser features allow many people to have accounts in Linux, with their data kept secure from others. Multitasking allows many people to use the computer at the same time. Sophisticated networking protocols and applications make it possible for a Linux system to extend its capabilities to network users and computers around the world. The person assigned to manage all of this stuff is referred to as the system administrator.
Even if you are the only person using a Linux system, system administration is still set up to be separate from other computer use. To do most administrative tasks, you need to be logged in as the
root user (also referred to as the super user) or gain temporary root privilege. Other users cannot change, or in some cases, even see some of the configuration information for a Linux system. In particular, security features such as passwords are protected from general view.
This chapter describes the general principles of administering a CentOS system. In particular, this chapter covers some of the basic tools you need to administer your Linux system. It ...