Chapter 27: Basic System Administration

Overview

Linux is designed to serve many users at the same time, providing an interface between the users and the system with its resources, services, and devices. Users have their own shells through which they interact with the operating system, but you may need to configure the operating system itself in different ways. You may need to add new users, devices like printers and scanners, and even file systems. Such operations come under the heading of system administration. The person who performs such actions is referred to as either a system administrator or a superuser. In this sense, there are two types of interaction with Linux: regular users' interaction, and the superuser, who performs system administration tasks. The chapters in this book cover operations such as changing system runlevels, managing users, configuring printers, adding file systems, and compiling the kernel. You perform most of these tasks only rarely, such as adding a new printer or mounting a file system. Other tasks, such as adding or removing users, you perform on a regular basis. Basic system administration covers topics such as system access by superusers, selecting the run level to start, system configuration files, and performance monitoring.

With Linux, you have the ability to load different versions of the Linux kernel as well as other operating systems that you have installed on your system. The task of selecting and starting up an operating system or kernel is managed by a boot management utility, the Grand Unified Bootloader (GRUB). This is a versatile tool, letting you load operating systems that share the same disk drive, as well as letting you choose from different Linux kernels that may be installed on the same Linux system.

Backup operations have become an important part of administrative duties. Several backup tools are provided on Linux systems, including Anaconda and the traditional dump tool. Anaconda provides server-based backups, letting different systems on a network back up to a central server. The dump tools let you refine your backup process, detecting data changed since the last backup.