Filesystem Hierarchy Standard
This standard consists of a set of requirements and guidelines for file and directory placement under UNIX-like operating systems. The guidelines are intended to support interoperability of applications, system administration tools, development tools, and scripts as well as greater uniformity of documentation for these systems.
Copyright © 2025 FreeDesktop Filesystem Hierarchy Standard Project Contributors
Copyright © 2015-2025 The Linux Foundation
Copyright © 1994-2004 Daniel Quinlan
Copyright © 2001-2004 Paul 'Rusty' Russell
Copyright © 2003-2004 Christopher Yeoh
Dedication #
This release is dedicated to the memory of Christopher Yeoh, a long-time friend and colleague, and one of the original editors of the FHS. Without his dedication this work would not have been possible.
- 1 Introduction
- 2 The Filesystem
- 3 The Root Filesystem
- 3.1 Purpose
- 3.2 Requirements
- 3.3 Specific Options
- 3.4 /bin : Essential user command binaries (for use by all users)
- 3.5 /boot : Static files of the boot loader
- 3.6 /dev : Device files
- 3.7 /etc : Host-specific system configuration
- 3.8 /home : User home directories (optional)
- 3.9 /lib : Essential shared libraries and kernel modules
- 3.10 /lib<qual> : Alternate format essential shared libraries (optional)
- 3.11 /media : Mount point for removable media
- 3.12 /mnt : Mount point for a temporarily mounted filesystem
- 3.13 /opt : Add-on application software packages
- 3.14 /root : Home directory for the root user (optional)
- 3.15 /run : Run-time variable data
- 3.16 /sbin : System binaries
- 3.17 /srv : Data for services provided by this system
- 3.18 /tmp : Temporary files
- 4 The /usr Hierarchy
- 4.1 Purpose
- 4.2 Requirements
- 4.3 Specific Options
- 4.4 /usr/bin : Most user commands
- 4.5 /usr/include : Directory for standard include files.
- 4.6 /usr/lib : Libraries for programming and packages
- 4.7 /usr/libexec : Binaries run by other programs (optional)
- 4.8 /usr/lib<qual> : Alternate format libraries (optional)
- 4.9 /usr/local : Local hierarchy
- 4.10 /usr/sbin : Non-essential standard system binaries
- 4.11 /usr/share : Architecture-independent data
- 4.12 /usr/src : Source code (optional)
- 5 The /var Hierarchy
- 5.1 Purpose
- 5.2 Requirements
- 5.3 Specific Options
- 5.4 /var/account : Process accounting logs (optional)
- 5.5 /var/cache : Application cache data
- 5.6 /var/crash : System crash dumps (optional)
- 5.7 /var/games : Variable game data (optional)
- 5.8 /var/lib : Variable state information
- 5.9 /var/lock : Lock files
- 5.10 /var/log : Log files and directories
- 5.11 /var/mail : User mailbox files (optional)
- 5.12 /var/opt : Variable data for /opt
- 5.13 /var/run : Run-time variable data
- 5.14 /var/spool : Application spool data
- 5.15 /var/tmp : Temporary files preserved between system reboots
- 5.16 /var/yp : Network Information Service (NIS) database files (optional)
- 6 Operating System Specific Annex
- 7 Appendix
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