Navigating Linux File Structure: Essential Directories Explained

1. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree

2. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • root directory - / • Every single file and directory starts from the root directory. • Only root user has write privilege • “/root” is root user’s home directory -- not same as “/”

3. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /bin directory – user binaries • Contains binary executables. • Common commands you need to use in single-user modes are located under this directory. • Commands used by all the users of the system are located here. • /bin subdirectory • For example: ps, ls, ping, grep, cp. • Note:Binaries are files that contain compiled source code (or machine code).

4. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /sbin directory – system binaries • Just like /bin, /sbin also contains binary executables. • The linux commands located under this directory are used typically by system aministrator, for system maintenance purpose. • Contains binaries to configure the OS • Require “root” privilege • For example: iptables, reboot, fdisk, ifconfig, swapon • Note:Binaries are files that contain compiled source code (or machine code).

5. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /etc directory – Configuration files • Contains configuration files required by all programs. • startup and shutdown shell scripts used to start/stop individual programs. • For example: /etc/resolv.conf, /etc/logrotate.conf • Note:Binaries are files that contain compiled source code (or machine code).

6. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /device directory – Device files • Contains device files. • These include terminal devices, usb, or any device attached to the system. • Appear to be ordinary files • For example: ls /dev/sd* • Note:Binaries are files that contain compiled source code (or machine code).

7. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /proc directory – Process Info • Contains information about system process. • This is a pseudo filesystem contains information about running process. For example: ls/proc/{pid} directory contains information about the process with that particular pid. • This is a virtual filesystem with text information about system resources. For example: ls/proc/uptime • Note:Binaries are files that contain compiled source code (or machine code).

8. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /var directory – Variable files • var stands for variable files. • Content of the files that are expected to grow can be found under this directory. • This includes — system log files (/var/log); packages and database files (/var/lib); emails (/var/mail); print queues (/var/spool); lock files (/var/lock); temp files needed across reboots (/var/tmp); • Note:Binaries are files that contain compiled source code (or machine code).

9. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /tmp directory – Temporary files • Directory that contains temporary files created by system and users. • Files are deleted when system is rebooted. • Never store data here that is important • Note:Binaries are files that contain compiled source code (or machine code).

10. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /usr directory – User Programs • “usr” stands for Unix System Resources • Contains binaries, libraries, documentation, and source-code for second level programs. • /usr/bin contains binary files for user programs. • /usr/sbin contains binary files for system administrators. For example: atd, cron, sshd, useradd, userdel • /usr/lib contains libraries for /usr/bin and /usr/sbin • /usr/local contains users programs that you install from source. For example: when you install apache from source, it goes under /usr/local/apache2 • Note:Binaries are files that contain compiled source code (or machine code).

11. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /home directory – Home Directories • Home directories for all users to store their personal files. • Common to name users home directory after user name • For example: /home/john, /home/nikita • Note:Binaries are files that contain compiled source code (or machine code).

12. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /boot directory – Boot loader files • Contains boot loader related files. • All files needed to boot the computer • Don’t change very often • Kernel initrd, vmlinux, grub files are located under /boot • Note:Binaries are files that contain compiled source code (or machine code).

13. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /lib directory – System Libraries • Contains library files that supports the binaries located under /bin and /sbin • Library filenames are either ld* or lib*.so.* • Note:Binaries are files that contain compiled source code (or machine code).

14. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /opt directory – Optional add-on Apps • opt stands for optional. • Contains add-on applications from individual vendors. • add-on applications should be installed under either /opt/ or /opt/ sub-directory • Software outside the distribution repository • Note:Binaries are files that contain compiled source code (or machine code).

15. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /mnt directory – Mount directory • Temporary mount directory where sysadmins can mount filesystems • Should be empty and only used for temporary mount points • Note:Binaries are files that contain compiled source code (or machine code).

16. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /media directory – Removable Media Devices • Temporary mount directory for removable devices. • For examples: /media/cdrom for CD-ROM; /media/floppy for floppy drives; /media/cdrecorder for CD writer • Note:Binaries are files that contain compiled source code (or machine code).

17. Linux Administration – Finding You Way on the Command Line The Linux File Directory or Tree • /srv directory – Service Data • srv stands for service. • Use /srv for data that is served by your system • FHS allows locating cvs, rsync, ftp and www data • Note:Binaries are files that contain compiled source code (or machine code).