System Directories

Your Linux file system is organized into directories whose files are used for different system functions (see Table 27-6). For basic system administration, you should be familiar with the system program directories where applications are kept, the system configuration directory (/etc) where most configuration files are placed, and the system log directory (/var/log) that holds the system logs, recording activity on your system. Other system directories are covered in their respective chapters, with many discussed in Chapter 30.

Table 27-5: Red Hat Configuration Tools
Red Hat Administration Tool	Description
System Settings	Red Hat window and menu for accessing administrative tools
redhat-config-users	User and Group configuration tool
redhat-config-printer	Printer configuration tool
redhat-config-xfree86	Red Hat display configuration tool (video card and monitor)
redhat-config-packages	Software management
redhat-config-rootpassword	Changes the root user password
redhat-config-keyboard	Changes the keyboard configuration
redhat-config-date	Changes system time and date
redhat-config-mouse	Configures your mouse
redhat-config-language	Selects a language to use
redhat-config-soundcard	Configures your sound card

Table 27-6: System Directories
Directories	Description
/bin	System-related programs
/sbin	System programs for specialized tasks
/lib	System libraries
/etc	Configuration files for system and network services and applications
/home	The location of user home directories and server data directories, such as Web and FTP site files
/mnt	The location where CD-ROM and floppy disk files systems are mounted (Chapter 30)
/var	The location of system directories whose files continually change, such as logs, printer spool files, and lock files (Chapter 30)
/usr	User-related programs and files; includes several key subdirectories, such as /usr/bin, /usr/X11, and /usr/doc
/usr/bin	Programs for users
/dev	Device files (Chapter 32)
/usr/X11	X Window System configuration files
/usr/share	Shared files
/usr/share/doc	Documentation for applications
/tmp	Directory for system temporary files

Program Directories

Directories with "bin" in the name are used to hold programs. The /bin directory holds basic user programs, such as login, shells (BASH, TCSH, and ZSH), and file commands (cp, mv, rm, ln, and so on). The /sbin directory holds specialized system programs for such tasks as file system management (fsck, fdisk, mkfs) and system operations like shutdown and startup (init). The /usr/bin directory holds program files designed for user tasks. The /usr/sbin directory holds user-related system operations, such as useradd to add new users. The /lib directory holds all the libraries your system makes use of, including the main Linux library, libc, and subdirectories such as modules, which holds all the current kernel modules.