Filesystem Hierarchy Standard (FHS)

Folder Word/expression Description FSSTND / FHS UNIX
/ Root folder The starting point of the file system. Primary hierarchy.
/bin Binaries Location of basic executable binary files.
/boot Boot Location of files required for system boot. Bootloader (e.g. grub), kernel, initrd…
/dev Devices Hardware and other device access points.
/etc Et cetera (latin) → Everything to configure Location of system-wide configuration files.
/etc/opt Optional Configurations of add-on packages.
/etc/sgml Standard Generalized Markup Language Configuration files, catalogs for SGML processing software.
/etc/X11 X Window System 11. version Configuration files for X Window System 11.
/etc/xml Extensible Markup Language Configuration files, directories for XML processing software.
/home Home Collection of users’ folders.
/lib Libraries Shared (program) libraries and kernel modules.
/lib32 Libraries Optionally 32-bit platform-dependent shared (program)libraries and kernel modules.
/lib64 Libraries Optionally 64-bit platform-dependent shared (program)libraries and kernel modules.
/lost+found Lost, Found Recovered files. ← fsck, e.g. ext4 file system
/media Media Used to mount portable media (e.g. pendrive, optical or floppy disk). ✅ 2.3 (2004)
/mnt Mount Used to temporarily mount file systems.
/opt Optional Add-on application software packages.
/proc Processes Running processes and kernel information in a virtual file system.
/root Root ← Administrator Home folder of the system administrator (root) user.
/run Run Provides access to running processes. ✅ 3.0 (2015)
/sbin Superuser's (system’s) binaries Location of basic system binaries.
/snap Snap Files belonging to the snap package manager.
/srv Server Location of data related to services (server programs). ✅ 2.3 (2004)
/sys System Information about devices and the kernel. In BSD, the kernel source.
/tmp Temporary Location of temporary files.
/unix UNIX – UNICS Kernel (System V, Research UNIX).
/usr User Secondary hierarchy.
/usr/bin User / Binaries Takes the place of /bin on many systems.
/usr/include User / Includes Typically C header files.
/usr/lib User / Libraries Takes the place of /lib on many systems.
/usr/lib32 User / Libraries Replaces /lib32 on many systems.
/usr/lib64 User / Libraries Replaces /lib64 on many systems.
/usr/libexec User / Executable libraries Executables used by other programs (or even standalone ones).
/usr/local User / Local Tertiary hierarchy. Local hierarchy (e.g. bin, lib, man, etc…).
/usr/local/share User / Local / Share Shared local resources (wallpapers, icons, etc.).
/usr/sbin User / Superuser's binaries Replaces /sbin on many systems.
/usr/share User / Share Shared resources (wallpapers, icons, man pages, etc.).
/usr/src Sources Source code.
/usr/X11R6 User / X Window System 11. version release 6. Files for X Window System 11 (R6). ✅ 2.3 (2004)
/var Variable Variable data.
/var/cache Variable / Cache Application cache data.
/var/lib Variable / Libraries Status information. Persistent data modified during runtime.
/var/lock Variable / Lock Resource lock files.
/var/log Variable / Log (logbook) Log files.
/var/mail Variable / Mail Files from some email programs.
/var/opt Variable / Optional Variable data from add-on packages.
/var/run Variable / Run Runtime variable data. /run has taken over since FHS 3.0 (but the link is mandatory).
/var/spool Variable / Spool (~queue) Mail, print, or proxy data. (E.g. stuff that has a queue…)
/var/spool/mail Variable / Spool / Mail Original location of /var/mail. Some programs may still use it.
/var/src Variable / Sources Uncompiled sources of some programs.
/var/tmp Variable / Temporary Temporary files (e.g. between system boots).
/var/www Variable / World Wide Web HTTP server document folder.
/vmunix Virtual Memory + UNIX – UNICS UNIX virtual memory (3BSD).
Version Date Linux Foundation Standard
1.0 1994.02.14 FSSTND (Filesystem Standard)
1.1 1994.10.09 FSSTND
1.2 1995.03.28 FSSTND
2.0 1997.10.26 FHS (Filesystem Hierarchy Standard)
2.1 2000.04.12 FHS
2.2 2001.05.23 FHS
2.3 2004.01.29 FHS
3.0 2015.05.18 FHS
Copyright © 2020–2026. Tom Károly