RHEL Directory Structure (File System Structure)

1. / – Root

§  Every single file and directory starts from the root directory.

§  Only root user has write privilege under this directory.

§  Please note that /root is root user’s home directory, which is not same as /.

2. /bin – User Binaries

§  Contains binary executables.

§  Common linux 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.

§  For example: ps, ls, ping, grep, cp.

3. /sbin – System Binaries

§  Just like /bin, /sbin also contains binary executables.

§  But, the linux commands located under this directory are used typically by system aministrator, for system maintenance purpose.

§  For example: iptables, reboot, fdisk, ifconfig, swapon

4. /etc – Configuration Files

§  Contains configuration files required by all programs.

§  This also contains startup and shutdown shell scripts used to start/stop individual programs.

§  For example: /etc/resolv.conf, /etc/logrotate.conf

5. /dev – Device Files

§  Contains device files.

§  These include terminal devices, usb, or any device attached to the system.

§  For example: /dev/tty1, /dev/usbmon0

6. /proc – Process Information

§  Contains information about system process.

§  This is a pseudo filesystem contains information about running process. For example: /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: /proc/uptime

7. /var – 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);

8. /tmp – Temporary Files

§  Directory that contains temporary files created by system and users.

§  Files under this directory are deleted when system is rebooted.

9. /usr – User Programs

§  Contains binaries, libraries, documentation, and source-code for second level programs.

§  /usr/bin contains binary files for user programs. If you can’t find a user binary under /bin, look under /usr/bin. For example: at, awk, cc, less, scp

§  /usr/sbin contains binary files for system administrators. If you can’t find a system binary under /sbin, look under /usr/sbin. 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

10. /home – Home Directories

§  Home directories for all users to store their personal files.

§  For example: /home/john, /home/nikita

11. /boot – Boot Loader Files

§  Contains boot loader related files.

§  Kernel initrd, vmlinux, grub files are located under /boot

§  For example: initrd.img-2.6.32-24-generic, vmlinuz-2.6.32-24-generic

12. /lib – System Libraries

§  Contains library files that supports the binaries located under /bin and /sbin

§  Library filenames are either ld* or lib*.so.*

§  For example: ld-2.11.1.so, libncurses.so.5.7

13. /opt – Optional add-on Applications

§  opt stands for optional.

§  Contains add-on applications from individual vendors.

§  add-on applications should be installed under either /opt/ or /opt/ sub-directory.

14. /mnt – Mount Directory

§  Temporary mount directory where sysadmins can mount filesystems.

15. /media – 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

16. /srv – Service Data

§  srv stands for service.

§  Contains server specific services related data.

§  For example, /srv/cvs contains CVS related data.