Filesystem Hierarchy Standard

Abstract

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.

Table of Contents

• Copyright and License
• 1 Introduction
  • 1.1 Status of the Standard
  • 1.2 Organization of the Standard
  • 1.3 Conventions
  • 1.4 Background of the FHS
  • 1.5 Scope
  • 1.6 General Guidelines
  • 1.7 Intended Audience
  • 1.8 Conformance with this Document
• 2 The Filesystem
• 3 The Root Directory
  • 3.1 /bin : Essential user command binaries (for use by all users)
  • 3.2 /boot : Static files of the boot loader
  • 3.3 /dev : Device files
  • 3.4 /etc : Host-specific system configuration
    • 3.4.1 /etc/X11 : Configuration for the X Window System
    • 3.4.2 /etc/opt : Configuration files for /opt
  • 3.5 /home : User home directories (optional)
  • 3.6 /lib : Essential shared libraries and kernel modules
  • 3.7 /mnt : Mount point for temporarily mounted filesystems
  • 3.8 /opt : Add-on application software packages
  • 3.9 /root : Home directory for the root user (optional)
  • 3.10 /sbin : System binaries (binaries once kept in /etc)
  • 3.11 /tmp : Temporary files
• 4 The /usr Hierarchy
  • 4.1 /usr/X11R6 : X Window System, Version 11 Release 6
  • 4.2 /usr/X386 : X Window System, Version 11 Release 5, on x86 platforms
  • 4.3 /usr/bin : Most user commands
  • 4.4 /usr/include : Directory for standard include files.
  • 4.5 /usr/lib : Libraries for programming and packages
  • 4.6 /usr/local : Local hierarchy
  • 4.7 /usr/sbin : Non-essential standard system binaries
  • 4.8 /usr/share : Architecture-independent data
    • 4.8.1 /usr/share/dict : Word lists
    • 4.8.2 /usr/share/man : Manual pages
    • 4.8.3 /usr/share/misc : Miscellaneous architecture-independent data
  • 4.9 /usr/src : Source code
• 5 The /var Hierarchy
  • 5.1 /var/account : Process accounting logs (if supported)
  • 5.2 /var/cache : Application cache data
    • 5.2.1 /var/cache/fonts : Locally-generated fonts
    • 5.2.2 /var/cache/man : Locally-formatted manual pages (optional)
  • 5.3 /var/crash : System crash dumps (if supported)
  • 5.4 /var/games : Variable game data
  • 5.5 /var/lock : Lock files
  • 5.6 /var/log : Log files and directories
  • 5.7 /var/mail : User mailbox files
  • 5.8 /var/opt : Variable data for /opt
  • 5.9 /var/run : Run-time variable files
  • 5.10 /var/spool : Application spool data
    • 5.10.1 /var/spool/lpd : Line-printer daemon print queues
    • 5.10.2 /var/spool/rwho : Rwhod files
  • 5.11 /var/state : Variable state information
    • 5.11.1 /var/state/<editor> : Editor backup files and state
    • 5.11.2 /var/state/misc : Miscellaneous variable data
  • 5.12 /var/tmp : Temporary files preserved between system reboots
  • 5.13 /var/yp : Network Information Service (NIS) database files
• 6 Operating System Specific Annex
  • 6.1 Linux
    • 6.1.1 / : Root directory
    • 6.1.2 /dev : Devices and special files
    • 6.1.3 /proc : Kernel and process information virtual filesystem
    • 6.1.4 /sbin : Essential system binaries
    • 6.1.5 /usr/include : Header files included by C programs
    • 6.1.6 /usr/src : Source code
    • 6.1.7 /var/spool/cron : cron and at jobs
• FHS mailing list
• Acknowledgements