Open In App

Linux File Hierarchy Structure

Last Updated : 09 Jun, 2023
Improve
Improve
Like Article
Like
Save
Share
Report

The Linux File Hierarchy Structure or the Filesystem Hierarchy Standard (FHS) defines the directory structure and directory contents in Unix-like operating systems. It is maintained by the Linux Foundation. 

  • In the FHS, all files and directories appear under the root directory /, even if they are stored on different physical or virtual devices.
  • Some of these directories only exist on a particular system if certain subsystems, such as the X Window System, are installed.
  • Most of these directories exist in all UNIX operating systems and are generally used in much the same way; however, the descriptions here are those used specifically for the FHS and are not considered authoritative for platforms other than Linux.
linux-directory

linux-directory

1. / (Root): 

Primary hierarchy root and root directory of the entire file system hierarchy. 

  • Every single file and directory start from the root directory.
  • The only root user has the right to write under this directory.
  • /root is the root user’s home directory, which is not the same as /
root-linux-directory

root-linux-directory

2. /bin : 

Essential command binaries that need to be available in single-user mode; for all users, e.g., cat, ls, cp. 

  • 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 e.g. ps, ls, ping, grep, cp 
bin-linux-directory

bin-linux-directory

3. /boot :

 Boot loader files, e.g., kernels, initrd. 
 

  • Kernel initrd, vmlinux, grub files are located under /boot
  • Example: initrd.img-2.6.32-24-generic, vmlinuz-2.6.32-24-generic
boot-linux-directory

boot-linux-directory

4. /dev :

 Essential device files, e.g., /dev/null. 

  • These include terminal devices, usb, or any device attached to the system.
  • Example: /dev/tty1, /dev/usbmon0
dev-linux-directory

dev-linux-directory

5. /etc :

 Host-specific system-wide configuration files.

  • Contains configuration files required by all programs.
  • This also contains startup and shutdown shell scripts used to start/stop individual programs.
  • Example: /etc/resolv.conf, /etc/logrotate.conf.
etc-linux-directory

etc-linux-directory

6. /home :

 Users’ home directories, containing saved files, personal settings, etc.

  • Home directories for all users to store their personal files.
  • example: /home/kishlay, /home/kv

home-linux-directory

home-linux-directory

home-linux-directory

home-linux-directory

7. /lib:

 Libraries essential for the binaries in /bin/ and /sbin/.

  • Library filenames are either ld* or lib*.so.*
  • Example: ld-2.11.1.so, libncurses.so.5.7
lib-linux-directory

lib-linux-directory

8. /media:

 Mount points for removable media such as CD-ROMs (appeared in FHS-2.3).

  • Temporary mount directory for removable devices.
  • Examples, /media/cdrom for CD-ROM; /media/floppy for floppy drives; /media/cdrecorder for CD writer
media-linux-directory

media-linux-directory

9. /mnt :

 Temporarily mounted filesystems.

  • Temporary mount directory where sysadmins can mount filesystems.
mnt-linux-directory

mnt-linux-directory

10. /opt : 

Optional application software packages.

  • Contains add-on applications from individual vendors.
  • Add-on applications should be installed under either /opt/ or /opt/ sub-directory.
opt-linux-directory

opt-linux-directory.

11. /sbin : 

Essential system binaries, e.g., fsck, init, route.

  • Just like /bin, /sbin also contains binary executables.
  • The linux commands located under this directory are used typically by system administrators, for system maintenance purposes.
  • Example: iptables, reboot, fdisk, ifconfig, swapon

sbin-linux-directory

12. /srv : 

Site-specific data served by this system, such as data and scripts for web servers, data offered by FTP servers, and repositories for version control systems.

  • srv stands for service.
  • Contains server specific services related data.
  • Example, /srv/cvs contains CVS related data.
srv-linux-directory

srv-linux-directory

13. /tmp : 

Temporary files. Often not preserved between system reboots and may be severely size restricted.

  • Directory that contains temporary files created by system and users.
  • Files under this directory are deleted when the system is rebooted.
tmp-linux-directory

tmp-linux-directory

14. /usr : 

Secondary hierarchy for read-only user data; contains the majority of (multi-)user utilities and applications. 
 

  • 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 user’s programs that you install from source. For example, when you install apache from source, it goes under /usr/local/apache2
  • /usr/src holds the Linux kernel sources, header-files and documentation. 

usr_bin-linux-directory

usr_bin-linux-directory

usr_sbin-linux-directory

usr_sbin-linux-directory

usr_lib-linux-dirctory

usr_lib-linux-dirctory

usr_local-linux-directory

usr_local-linux-directory

usr_src-linux-directory

usr_src-linux-directory

15. /proc:

 Virtual filesystem providing process and kernel information as files. In Linux, it corresponds to a procs mount. Generally, automatically generated and populated by the system, on the fly.

  • Contains information about system process.
  • This is a pseudo filesystem that contains information about running processes. 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

proc-linux-directory

proc-linux-directory

proc-linux-directory

proc-linux-directory

Modern Linux distributions include a /run directory as a temporary filesystem (tmpfs) which stores volatile runtime data, following the FHS version 3.0. According to the FHS version 2.3, such data were stored in /var/run but this was a problem in some cases because this directory is not always available at early boot. As a result, these programs have had to resort to trickery, such as using /dev/.udev, /dev/.mdadm, /dev/.systems or /dev/.mount directories, even though the device directory isn’t intended for such data.Among other advantages, this makes the system easier to use normally with the root filesystem mounted read-only. For example, below are the changes Debian made in its 2013 Wheezy release:

  • /dev/.* ? /run/*
  • /dev/shm ? /run/shm
  • /dev/shm/* ? /run/*
  • /etc/* (writable files) ? /run/*
  • /lib/init/rw ? /run
  • /var/lock ? /run/lock
  • /var/run ? /run
  • /tmp ? /run/tmp

 

?list=PLqM7alHXFySFc4KtwEZTANgmyJm3NqS_L 
See your article appearing on the GeeksforGeek’s main page and help other Geeks. 

 



Previous Article
Next Article

Similar Reads

Static Data Structure vs Dynamic Data Structure
Data structure is a way of storing and organizing data efficiently such that the required operations on them can be performed be efficient with respect to time as well as memory. Simply, Data Structure are used to reduce complexity (mostly the time complexity) of the code. Data structures can be two types : 1. Static Data Structure 2. Dynamic Data
4 min read
Linux Virtualization : Linux Containers (lxc)
Operating-system-level virtualization is a server virtualization method in which an operating system's kernel allows multiple isolated user-space instances, instead of just one. Such instances, which are sometimes called containers, software containers, virtualization engines (VEs), or jails (FreeBSD jail or chroot jail), may look and feel like a r
6 min read
How to View the Content of File in Linux | cat Command
The cat command in Linux is more than just a simple tool; it's a versatile companion for various file-related operations, allowing users to view, concatenate, create, copy, merge, and manipulate file contents. Let's delve into the details of some frequently used cat commands, understanding each example along the way. Table of Content Basic Syntax o
7 min read
Services and Segment structure in TCP
The Transmission Control Protocol is the most common transport layer protocol. It works together with IP and provides a reliable transport service between processes using the network layer service provided by the IP protocol. The various services provided by the TCP to the application layer are as follows: Process-to-Process Communication - TCP pro
5 min read
Data Structure to Design a special social network
Consider a special social network where people are called connected if one person is connected to other with any number of intermediate connections. For example if a person x is connected with y and y is connected with z, then x is also considered to be connected with z. We are given a set of friend requests as input. We are also given a set of que
4 min read
Remove duplicates from unsorted array using Set data structure
Given an unsorted array of integers, print the array after removing the duplicate elements from it. We need to print distinct array elements according to their first occurrence. Examples: Input: arr[] = { 1, 2, 5, 1, 7, 2, 4, 2} Output: 1 2 5 7 4 Explanation: {1, 2} appear more than one time. Input: arr[] = { 3, 3, 4, 1, 1} Output: 3 4 1 Approach:
3 min read
The Structure of ERP
Introduction :The essence of ERP is the fundamental approach that takes an integrated view of the subject. The established application systems, which the organization generally employs, treat each deal separately. They are built around the strong boundaries of specific functions that a specific application is meant to carter. Features of the Struct
3 min read
Difference Between Structure and Union in C
Structures in C is a user-defined data type available in C that allows to combining of data items of different kinds. Structures are used to represent a record. Defining a structure: To define a structure, you must use the struct statement. The struct statement defines a new data type, with more than or equal to one member. The format of the struct
4 min read
Flexible Array Members in a structure in C
Flexible Array Member(FAM) is a feature introduced in the C99 standard of the C programming language. For the structures in C programming language from C99 standard onwards, we can declare an array without a dimension and whose size is flexible in nature.Such an array inside the structure should preferably be declared as the last member of the stru
4 min read
Useful and time saving bash commands in Linux
There are many useful bash scripts that can make things easier. Many things can be done just using the terminal. Here is a list of some of such useful bash scripts through which we can do things that cannot be done manually. 1. Counting the number of files(or directory) in a given directory: Go to the directory in which you want to count the number
3 min read
Article Tags :
Practice Tags :