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Important Directories and Files

Important Directories

/bin                            holds the “essential” Linux commands and utilities
/boot                          holds files required for boot process (kernel, vmlinuz, grub)
/dev                            holds device files (hard drive, USB, CD-ROM, etc.)
/etc                             holds system configuration files
/etc/init.d                    holds scripts to start/stop network services
/etc/rc.d                     holds system startup/shutdown scripts
/etc/X11                      holds configuration files for X-windows
/home                        holds user home directories (except for the root account)
/lib                               holds system/shared library files
/lost+found                holds files restored after system crash
/mnt                            used as temporary mount point for CD-ROM, floppy, etc.
/opt                              typically where large software applications are installed
/proc                           holds kernel and process information
/root                            home directory for the root account (not /home/root)
/sbin                           like /bin but holds commands used by root/admin users
/tmp                             used as temporary file space
/usr                             holds user-related programs and files
/usr/bin                       holds commands/utilities that are outside of the “essential” list
/usr/lib                        holds libraries for installed packages
/usr/local                    holds files and data developed or customized on system
/usr/share/doc           holds Linux application documentation
/usr/share/man         holds Linux man pages
/var holds                   files that “vary” in size (log files, spools)
/var/www                    frequently used as the root directory for apache web servers
/var/log                       holds many (but not all) log files

Important & Useful Files

/boot/grub/menu.lst configuration file for GRUB
/etc/bashrc                 global profile for all bash shell users on the system (ex: alias)
/etc/issue                   name and version of Linux system shown at login prompt
/etc/fstab                    filesystems that are automatically mounted on bootup
/etc/inittab                  specifies runlevel and processes that are started at bootup
/etc/modules.conf    configuration of kernel modules that are loaded at bootup
/etc/nologin               if present it will refuse all non-root logins and display the
contents of nologin file
/etc/profile                  global profile for all users regardless of shell
/etc/sudoers              defines who has sudo access
/etc/syslog.conf        configuration for log files. Also see /etc/logrotate.conf
/etc/sysctl.conf          configuration file for system controls (ex: ignore ping)
/etc/X11/xorg.conf    configuration file for X-windows
/proc/cpuinfo             information about system CPU (try: cat /proc/cpuinfo)

/proc/meminfo           information about system memory (try: cat /proc/meminfo)


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