View source for Filesystem Hierarchy Standard

{{Short description|Linux standard for directory structure}}
{{Use dmy dates|date=November 2021}}
{{Infobox technology standard
| title             = Filesystem Hierarchy Standard
| status            = Published
| year_started      = {{Start date and age|1994|02|14|df=yes}}
| version           = 3.0
| version_date      = {{Start date and age|2015|06|03|df=yes}}
| organization      = [[FreeDesktop.org]]<br />Previously: [[Linux Foundation]]
| related_standards =
| abbreviation      = FHS
| domain            = [[Directory structure]]
| website           = {{Official website}}
}}

The '''Filesystem Hierarchy Standard''' ('''FHS''') is a reference describing the conventions used for the layout of [[Unix-like]] systems. It has been made popular by its use in [[Linux distribution]]s, but it is used by other Unix-like systems as well.<ref>{{Cite web |title=FHS |url=https://wiki.linuxfoundation.org/lsb/fhs |access-date=4 January 2022 |website=The Linux Foundation Wiki}}</ref> The latest version of the standard, version 3.0, was originally released on 3 June 2015 by the [[Linux Foundation]].<ref>{{Cite web |title=FHS 3.0 Released |url=https://wiki.linuxfoundation.org/lsb/fhs-30 |access-date=22 February 2023 |website=The Linux Foundation Wiki}}</ref> It was republished on 6 November 2025 by [[FreeDesktop]], which has since assumed maintenance of the specification.<ref>{{cite web |title=Filesystem Hierarchy Standard – Version 3.0 |url=https://specifications.freedesktop.org/fhs/ |publisher=FreeDesktop.org |date=6 November 2025 |access-date=6 November 2025}}</ref><ref>{{cite web |title=FreeDesktop.org Adopts The Filesystem Hierarchy Standard |url=https://www.phoronix.com/news/FreeDesktop-Adopts-FHS |website=Phoronix |date=6 November 2025 |access-date=6 November 2025}}</ref>

== Directory structure ==
[[File:Root directory hierarchy on Linux screenshot.webp|300px|thumb|Filesystem hierarchy in [[openSUSE]]]]
In the FHS, all files and [[directory (file systems)|directories]] appear under the [[root directory]] <code>/</code>, even if they are stored on different physical or virtual devices. Some of these directories only exist in a particular system if certain subsystems, such as the [[X Window System]], are installed.

Most of these directories exist in all [[Unix-like]] 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.

{| class="wikitable" summary="A description of the hierarchy specified in the FHS."
|-
!Directory
!Description
|-
|<code>/</code>
|''Primary hierarchy'' root and [[root directory]] of the entire file system hierarchy.
|-
|<code>/bin</code>
|Essential command [[executable|binaries]] that need to be available in [[single-user mode]], including to bring up the system or repair it,<ref>{{Cite web |title=hier(7) |url=https://man7.org/linux/man-pages/man7/hier.7.html |access-date=6 January 2021 |website=man7.org}}</ref><ref>{{man|7|hier|Linux}}</ref> for all users (e.g., [[cat (Unix)|cat]], [[ls]], [[cp (Unix)|cp]]).
|-
|<code>[[Boot folder|/boot]]</code>
|[[Boot loader]] files (e.g., [[Kernel (operating system)|kernels]], [[initrd]]).
|-
|<code>[[/dev]]</code>
|[[Device file]]s (e.g., <code>[[Null device|/dev/null]]</code>, <code>/dev/disk0</code>,  <code>/dev/sda1</code>, <code>/dev/tty</code>, <code>[[/dev/random]]</code>).
|-
|<code>/etc</code>
<!-- Please see the talk page before changing this -->
|Host-specific system-wide [[configuration file]]s.<br />
There has been controversy over the meaning of the name itself. In early versions of the UNIX Implementation Document from Bell Labs, <code>/etc</code> is referred to as the ''[[et cetera|etcetera]] directory'',<ref>{{cite book |last=DeFelice |first=J. |url=http://www.bitsavers.org/pdf/att/unix/Early_UNIX/PreliminaryUnixImplementationDocument_Jun72.pdf |title=Preliminary Release of UNIX Implementation Document |date=17 March 1972 |page=8 |section=E.0 |id=IMO.1-1 |access-date=6 June 2024 |issue=D}}</ref> as this directory historically held everything that did not belong elsewhere (however, the FHS restricts <code>/etc</code> to static configuration files and may not contain binaries).<ref name="/etc">{{cite web |title=/etc : Host-specific system configuration |url=http://www.pathname.com/fhs/pub/fhs-2.3.html#ETCHOSTSPECIFICSYSTEMCONFIGURATION |access-date=18 February 2016 |work=Filesystem Hierarchy Standard 2.3}}</ref> Since the publication of early documentation, the directory name has been re-explained in various ways. Later interpretations include [[backronym]]s such as "Editable Text Configuration" or "Extended Tool Chest".<ref>{{cite web |last=Cliff |date=3 March 2007 |title=Define - /etc? |url=http://ask.slashdot.org/article.pl?sid=07/03/03/028258 |access-date=5 October 2025 |website=ask.slashdot.org}}</ref>
|-
|<code>/etc/opt</code>
|Configuration files for add-on packages stored in <code>/opt</code>.
|-
|<code>/etc/sgml</code>
|Configuration files, such as catalogs, for software that processes [[SGML]].
|-
|<code>/etc/X11</code>
|Configuration files for the [[X Window System]], version 11.
|-
|<code>/etc/xml</code>
|Configuration files, such as catalogs, for software that processes [[XML]].
|-
|<code>/home</code>
|Users' [[home directory|home directories]], containing saved files, personal settings, etc.
|-
|<code>/lib</code>
|[[Library (computer science)|Libraries]] essential for the [[binaries]] in <code>/bin</code> and <code>/sbin</code>.
|-
|<code>/lib&lt;qual&gt;</code>
|Alternate format essential libraries. These are typically used on systems that support more than one executable code format, such as systems supporting [[32-bit]] and [[64-bit]] versions of an [[instruction set]].  Such directories are optional, but if they exist, they have some requirements.
|-
|<code>/media</code>
|Mount points for [[removable media]] such as [[CD-ROM]]s (appeared in FHS-2.3 in 2004).
|-
|<code>/mnt</code>
|Temporarily [[mount (computing)|mounted]] filesystems.
|-
|<code>/opt</code>
|Add-on [[application software]] [[Software package (installation)|packages]].<ref name="/opt">{{cite web |title=/opt : Add-on application software packages |url=http://www.pathname.com/fhs/pub/fhs-2.3.html#OPTADDONAPPLICATIONSOFTWAREPACKAGES |access-date=18 February 2016 |work=Filesystem Hierarchy Standard 2.3}}</ref>
|-
|<code>[[/proc]]</code>
|Virtual [[File system|filesystem]] providing [[process (computing)|process]] and [[kernel (operating system)|kernel]] information as files. In Linux, corresponds to a [[procfs]] mount. Generally, automatically generated and populated by the system, on the fly.
|-
|<code>/root</code>
|[[Home directory]] for the [[superuser|root]] user.
|-
|<code>/run</code>
|Run-time variable data: Information about the running system since last boot, e.g., currently logged-in users and running [[Daemon (computer software)|daemons]]. Files under this directory must be either removed or truncated at the beginning of the boot process, but this is not necessary on systems that provide this directory as a [[temporary filesystem]] ([[tmpfs]]) (appeared in FHS-3.0 in 2015).
|-
|<code>/sbin</code>
|Essential system binaries (e.g., [[fsck]], [[init]], [[route (command)|route]]).
|-
|<code>/srv</code>
|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]] (appeared in FHS-2.3 in 2004).
|-
|<code>[[/sys]]</code>
|Contains information about devices, drivers, and some kernel features.<ref name="/sys">{{cite web |title=/sys : Kernel and system information virtual filesystem |url=https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch06.html#sysKernelAndSystemInformation |access-date=4 June 2017 |work=Filesystem Hierarchy Standard 3.0}}</ref>
|-
|<code>/tmp</code>
|[[Temporary folder|Directory for temporary files]] (see also <code>/var/tmp</code>). Often not preserved between system reboots and may be severely size-restricted.
|-
|<code>/usr</code>
<!-- ##### Please SEE THE TALK PAGE before changing this ##### -->
|''Secondary hierarchy'' for read-only user data; contains the majority of ([[multi-user|multi-]])user utilities and applications.<ref group="NB">The name is historical, and dates back to when <code>/usr</code> was used for user home directories on [[Unix]]; see the entry for <code>/usr</code> in the table in {{section link|Unix filesystem|Conventional directory layout}}.</ref> Should be shareable and read-only.<ref>{{cite web |title=Chapter 4. The /usr Hierarchy |url=https://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html#THEUSRHIERARCHY |access-date=5 October 2025 |work=Filesystem Hierarchy Standard 2.3}}</ref><ref>{{cite web |title=Chapter 4. The /usr Hierarchy, Section 4.1 Purpose |url=https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html#purpose18 |access-date=5 October 2025  |work=Filesystem Hierarchy Standard 3.0}}</ref>
<!-- ##### /usr is NOT anything but the above. This has been rehashed plenty of times before and reverting misled souls like yourself is taking up roughly a third of every edit on this page (another third being the edits of misled souls such as yourself). This time, Wikipedia is right. ##### -->
|-
|<code>/usr/bin</code>
|Non-essential command [[executable|binaries]] (not needed in [[single-user mode]]); for all users.
|-
|<code>/usr/include</code>
|Standard [[header file|include files]].
|-
|<code>/usr/lib</code>
|[[Library (computer science)|Libraries]] for the [[binaries]] in <code>/usr/bin</code> and <code>/usr/sbin</code>.
|-
|<code>/usr/libexec</code>
|Binaries run by other programs that are not intended to be executed directly by users or shell scripts (optional).
|-
|<code>/usr/lib&lt;qual&gt;</code>
|Alternative-format libraries (e.g., <code>/usr/lib32</code> for 32-bit libraries on a 64-bit machine (optional)).
|-
|<code>/usr/local</code>
|''Tertiary hierarchy'' for local data, specific to this host. Typically has further subdirectories (e.g., <code>bin</code>, <code>lib</code>, <code>share</code>).<ref group="NB">Historically and strictly according to the standard, <code>/usr/local</code> is for data that must be stored on the local host (as opposed to <code>/usr</code>, which may be mounted across a network). Most of the time <code>/usr/local</code> is used for installing software/data that are ''not'' part of the standard operating system distribution (in such case, <code>/usr</code> would only contain software/data that ''are'' part of the standard operating system distribution). It is possible that the FHS standard may in the future be changed to reflect this de facto convention.</ref>
|-
|<code>/usr/sbin</code>
|Non-essential system binaries (e.g., [[Daemon (computer software)|daemons]] for various [[network service]]s).
|-
|<code>/usr/share</code>
|Architecture-independent (shared) data.
|-
|<code>/usr/src</code>
|[[Source code]] (e.g., the kernel source code with its header files).
|-
|<code>/usr/X11R6</code>
|[[X Window System]], Version 11, Release 6 (up to FHS-2.3, optional).
|-
|<code>/var</code>
|Variable files: files whose content is expected to continually change during normal operation of the system, such as logs, spool files, and temporary e-mail files.
|-
|<code>/var/cache</code>
|Application cache data. Such data are locally generated as a result of time-consuming I/O or calculation. The application must be able to regenerate or restore the data. The cached files can be deleted without loss of data.
|-
|<code>/var/lib</code>
|State information. Persistent data modified by programs as they run (e.g., databases, packaging system metadata, etc.).
|-
|<code>/var/lock</code>
|Lock files. Files keeping track of resources currently in use.
|-
|<code>/var/log</code>
|Log files. Various logs.
|-
|<code>/var/mail</code>
|Mailbox files. In some distributions, these files may be located in the deprecated <code>/var/spool/mail</code>.
|-
|<code>/var/opt</code>
|Variable data from add-on packages that are stored in <code>/opt</code>.
|-
|<code>/var/run</code>
|Run-time variable data. This directory contains system information data describing the system since it was booted.<ref>{{cite web |title=/var/run : Run-time variable data |url=https://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html#VARRUNRUNTIMEVARIABLEDATA |access-date=5 October 2025 |work=Filesystem Hierarchy Standard 2.3}}</ref><br />
In FHS 3.0, <code>/var/run</code> is replaced by <code>/run</code>; a system should either continue to provide a <code>/var/run</code> directory or provide a symbolic link from <code>/var/run</code> to <code>/run</code> for backward compatibility.<ref>{{cite web |title=5.13. /var/run : Run-time variable data |url=https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s13.html |access-date=5 October 2025 |work=Filesystem Hierarchy Standard 3.0}}</ref>
|-
|<code>/var/spool</code>
|[[Spooling|Spool]] for tasks waiting to be processed (e.g., print queues and outgoing mail queue). Formerly also contained user mailbox files at <code>/var/spool/mail</code>.<ref>{{cite web |title=File System Standard |url=https://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.pdf#page=42 |access-date=5 October 2025 |publisher=Linux Foundation |at=5.11.1. Purpose}}</ref>
|-
|<code>/var/tmp</code>
|Temporary files to be preserved between reboots.
|}

== FHS compliance ==
Most [[Linux distribution]]s follow the Filesystem Hierarchy Standard and declare it their own policy to maintain FHS compliance.<ref>{{cite web |title=Chapter 2. File System Structure and Maintenance |url=https://docs.redhat.com/en/documentation/Red_Hat_Enterprise_Linux/7/html/storage_administration_guide/ch-filesystem#s1-filesystem-fhs |access-date=5 October 2025 |publisher=[[Red Hat]]}}</ref><ref>{{cite book |last=Eckert |first=Jason W. |title=SUSE Linux Enterprise Server Administration (Course 3037) |date=12 May 2006 |publisher=Course Technology |isbn=978-1-4188-3731-0 |oclc=84900687 |ol=9875721M}}</ref><ref>{{cite web |title=9.1. File system hierarchy |url=https://www.debian.org/doc/debian-policy/ch-opersys.html#file-system-hierarchy |access-date=5 October 2025 |website=debian.org}}</ref><ref>{{cite web |title=LinuxFilesystemTreeOverview |url=https://help.ubuntu.com/community/LinuxFilesystemTreeOverview |access-date=5 October 2025 |website=Community Ubuntu Documentation}}</ref> [[GoboLinux]]<ref>{{cite web |last=Muhammad |first=Hisham |date=9 May 2003 |title=The Unix tree rethought: an introduction to GoboLinux |url=http://www.gobolinux.org/?page=k5 |access-date=4 October 2016 |website=gobolinux.org}}</ref> and [[NixOS]]<ref>{{cite conference |last1=Dolstra |first1=Eelco |last2=Löh |first2=Andres |date=September 2008 |title=NixOS: A Purely Functional Linux Distribution |url=https://nixos.org/~eelco/pubs/nixos-icfp2008-final.pdf |conference=ICFP 2008: 13th ACM SIGPLAN International Conference on Functional Programming |location=Victoria, British Columbia, Canada |pages=367–378 |access-date=5 October 2025 |conference-url=http://www.icfpconference.org/icfp2008/ |website=nixos.org}}</ref> provide examples of intentionally non-compliant filesystem implementations.

Some distributions generally follow the standard but deviate from it in some areas. The FHS is a "trailing standard", and so documents common practices at a point in time. Of course, times change, and distribution goals and needs call for experimentation. Some common deviations include:
* Modern Linux distributions include a <code>/sys</code> directory as a [[virtual filesystem]] ([[sysfs]], comparable to <code>/proc</code>, which is a [[procfs]]), which stores and allows modification of the devices connected to the system,<ref>{{cite web |title=5.3 About the /sys Virtual File System |url=http://docs.oracle.com/cd/E37670_01/E41138/html/ol_sysfs.html |url-status=deviated |archive-url=https://web.archive.org/web/20160708193213/https://docs.oracle.com/cd/E37670_01/E41138/html/ol_sysfs.html |archive-date=8 July 2016 |access-date=8 July 2016 |website=docs.oracle.com |publisher=Oracle}}</ref> whereas many traditional [[Unix-like]] operating systems use <code>/sys</code> as a [[symbolic link]] to the [[Kernel (operating system)|kernel]] source tree.<ref>{{cite book |last1=Lehey |first1=Greg |url=https://books.google.com/books?id=7Y5kfaRmtKUC |title=The Complete FreeBSD: Documentation from the Source |date=May 2003 |publisher=O'Reilly Media, Incorporated |isbn=978-0-596-00516-0 |edition=Fourth |publication-place=Beijing |pages=188, 609 |lccn=2003278281 |oclc=51780648 |ol=3707136M |orig-date=March 1997}}</ref>
* Many modern Unix-like systems (such as [[FreeBSD]] and [[OpenBSD]]) via their [[Ports collection|ports systems]] install third-party packages into <code>/usr/local</code>, while keeping code considered part of the operating system in <code>/usr</code>.
* Some Linux distributions no longer differentiate between <code>/lib</code> and <code>/usr/lib</code> and have <code>/lib</code> symlinked to <code>/usr/lib</code>.<ref>{{cite web |last=McRae |first=Allan |date=14 July 2014 |title=The /lib directory becomes a symlink |url=https://www.archlinux.org/news/the-lib-directory-becomes-a-symlink/ |url-status=live |archive-url=https://web.archive.org/web/20140909234433/https://www.archlinux.org/news/the-lib-directory-becomes-a-symlink/ |archive-date=9 September 2014 |access-date=14 December 2019 |website=archlinux.org}}</ref>
* Some Linux distributions no longer differentiate between <code>/bin</code> and <code>/usr/bin</code> and between <code>/sbin</code> and <code>/usr/sbin</code>. They may symlink <code>/bin</code> to <code>/usr/bin</code> and <code>/sbin</code> to <code>/usr/sbin</code>. Other distributions choose to consolidate all four, symlinking them to <code>/usr/bin</code>.<ref>{{cite web |last=McRae |first=Allan |date=3 June 2013 |title=Binaries move to /usr/bin requiring update intervention |url=https://www.archlinux.org/news/binaries-move-to-usrbin-requiring-update-intervention/ |url-status=live |archive-url=https://web.archive.org/web/20140910093202/https://www.archlinux.org/news/binaries-move-to-usrbin-requiring-update-intervention/ |archive-date=10 September 2014 |access-date=15 December 2019 |website=archlinux.org}}</ref>

Modern Linux distributions include a <code>/run</code> 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 <code>/var/run</code>, 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 workarounds, such as using <code>/dev/.udev</code>, <code>/dev/.mdadm</code>, <code>/dev/.systemd</code> or <code>/dev/.mount</code> directories, even though the device directory is not intended for such data.<ref>{{cite mailing list |last=Poettering |first=Lennart |title=What's this /run directory doing on my system and where does it come from? |mailing-list=devel@lists.fedoraproject.org |date=30 March 2011 |url=https://www.mail-archive.com/devel@lists.fedoraproject.org/msg23576.html |access-date=5 October 2025}}</ref> 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:<ref>{{cite web |title=ReleaseGoalsRunDirectory |url=http://wiki.debian.org/ReleaseGoals/RunDirectory |access-date=5 October 2025 |website=Debian Wiki}}</ref>
* <code>/dev/.*</code> → <code>/run/*</code>
* <code>/dev/shm</code> → <code>/run/shm</code>
* <code>/dev/shm/*</code> → <code>/run/*</code>
* <code>/etc/*</code> (writeable files) → <code>/run/* </code>
* <code>/lib/init/rw</code> → <code>/run</code>
* <code>/var/lock</code> → <code>/run/lock</code>
* <code>/var/run</code> → <code>/run</code>
* <code>/tmp</code> → <code>/run/tmp</code>

== History ==

FHS was created as the FSSTND (short for "Filesystem Standard"<ref>{{cite web |title=FSSTND FAQ page |url=http://www.ibiblio.org/pub/Linux/docs/fsstnd/old/FSSTND-FAQ |access-date=10 May 2016 |website=ibiblio.org}}</ref>), largely based on similar standards for other [[Unix-like]] operating systems, such as the [[Version 7 Unix]] {{mono|hier(7)}} from 1979,<ref>{{man|7|hier|v7}}</ref> the [[SunOS]] 4.x {{mono|filesystem(7)}}<ref>{{cite web |date=10 January 1988 |title=SunOS 4.1.3 manual page for filesystem(7) |url=https://man.freebsd.org/cgi/man.cgi?query=filesystem&manpath=SunOS+4.1.3 |access-date=5 October 2025 |website=man.freebsd.org |publisher=the FreeBSD Man Pages library}}</ref> and its successor, the [[Solaris (operating system)|Solaris]] {{mono|filesystem(7)}},<ref>{{man|7|filesystem|Solaris}}.</ref><ref>{{cite web |title=filesystem man page – Solaris 10 11/06 Man Pages |url=http://manpages.unixforum.co.uk/man-pages/unix/solaris-10-11_06/5/filesystem-man-page.html |url-status=dead |archive-url=https://archive.today/20070704090908/http://manpages.unixforum.co.uk/man-pages/unix/solaris-10-11_06/5/filesystem-man-page.html |archive-date=4 July 2007 |access-date=15 October 2011}}</ref> and the FreeBSD {{mono|hier(7)}}.<ref>{{man|7|hier|FreeBSD}}.</ref>

=== Release history ===

{| class="wikitable"
|-
! Version
! Release date
! Notes
|-
| {{Version|o|1.0}}
| 1994-02-14
| FSSTND<ref>{{cite web |title=Index of /pub/Linux/docs/fsstnd/old/fsstnd-1.0/ |url=http://www.ibiblio.org/pub/Linux/docs/fsstnd/old/fsstnd-1.0/ |access-date=16 October 2012 |publisher=Ibiblio.org}}</ref>
|-
| {{Version|o|1.1}}
| 1994-10-09
| FSSTND<ref>{{cite web |title=Index of /pub/Linux/docs/fsstnd/old/fsstnd-1.1/ |url=http://www.ibiblio.org/pub/Linux/docs/fsstnd/old/fsstnd-1.1/ |access-date=16 October 2012 |publisher=Ibiblio.org}}</ref>
|-
| {{Version|o|1.2}}
| 1995-03-28
| FSSTND<ref>{{cite web |title=Index of /pub/Linux/docs/fsstnd/old/ |url=http://www.ibiblio.org/pub/Linux/docs/fsstnd/old/ |access-date=16 October 2012 |publisher=Ibiblio.org}}</ref>
|-
| {{Version|o|2.0}}
| 1997-10-26
| FHS 2.0 is the direct successor for FSSTND 1.2. Name of the standard was changed to Filesystem Hierarchy Standard.<ref>{{cite web |title=FHS 2.0 Announcement |url=http://www.pathname.com/fhs/announce-2.0.html |access-date=16 October 2012 |publisher=Pathname.com}}</ref><ref name="Saborio">{{citation |last=Quinlan |first=Daniel |title=FHS 2.0 Announcement |date=14 March 2012 |work=BSD, Linux, Unix and The Internet – Research by Kenneth R. Saborio |url=http://www.informatica.co.cr/linux/research/1997/1117.htm |access-date=18 February 2016 |archive-url=https://web.archive.org/web/20160305100804/http://www.informatica.co.cr/linux/research/1997/1117.htm |archive-date=5 March 2016 |url-status=dead |location=San Jose, Costa Rica |publisher=Kenneth R. Saborio |orig-year=1997}}.</ref><ref>{{cite web |title=Index of /pub/Linux/docs/fsstnd/ |url=http://www.ibiblio.org/pub/Linux/docs/fsstnd/ |access-date=16 October 2012 |publisher=Ibiblio.org}}</ref>
|-
| {{Version|o|2.1}}
| 2000-04-12
| FHS<ref>{{cite web |last=Quinlan |first=Daniel |title=FHS 2.1 Announcement |url=http://www.pathname.com/fhs/announce-2.1.html |access-date=16 October 2012 |publisher=Pathname.com}}</ref><ref>{{cite mailing list |last=Quinlan |first=Daniel |title=FHS 2.1 is released |mailing-list=lists.debian.org |date=13 April 2000 |url=https://lists.debian.org/lsb-spec/2000/04/msg00005.html |access-date=5 October 2025}}</ref><ref name="jdiamond">{{cite web |date=12 April 2000 |editor-last=Quinlan |editor-first=Daniel |title=Filesystem Hierarchy Standard – Version 2.1, Filesystem Hierarchy Standard Group |url=http://cs.acadiau.ca/~jdiamond/Acadia-Linux-template-tutorial/resources/fhs-2.1.pdf |archive-url=https://web.archive.org/web/20120327075156/http://cs.acadiau.ca/~jdiamond/Acadia-Linux-template-tutorial/resources/fhs-2.1.pdf |archive-date=27 March 2012 |access-date=18 October 2012 |work=Acadia Linux Tutorials |publisher=Jodrey School of Computer Science, [[Acadia University]] |location=Wolfville, Nova Scotia, Canada}}</ref>
|-
| {{Version|o|2.2}}
| 2001-05-23
| FHS<ref name="fhs-2.2">{{cite web |date=23 May 2001 |editor1-last=Russell |editor1-first=Rusty |editor1-link=Rusty Russell |editor2-last=Quinlan |editor2-first=Daniel |title=Filesystem Hierarchy Standard – Version 2.2 final Filesystem Hierarchy Standard Group |url=http://www.pathname.com/fhs/pub/fhs-2.2.pdf |access-date=18 February 2016 |work=Filesystem Hierarchy Standard}}</ref>
|-
| {{Version|o|2.3}}
| 2004-01-29
| FHS<ref name="fhs-2.3">{{cite web |date=28 January 2004 |editor1-last=Russell |editor1-first=Rusty |editor1-link=Rusty Russell |editor2-last=Quinlan |editor2-first=Daniel |editor3-last=Yeoh |editor3-first=Christopher |title=Filesystem Hierarchy Standard – Filesystem Hierarchy Standard Group |url=https://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.pdf |access-date=29 November 2014}}</ref>
|-
| {{Version|c|3.0}}
| 2015-05-18
| FHS<ref>{{cite web |date=19 March 2015 |editor1-last=Yeoh |editor1-first=Christopher |editor2-last=Russell |editor2-first=Rusty |editor2-link=Rusty Russell |editor3-last=Quinlan |editor3-first=Daniel |title=Filesystem Hierarchy Standard |url=https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.pdf |access-date=20 May 2015 |publisher=[[The Linux Foundation]]}}</ref>
|-
| colspan="3" | <small>{{Version |l |show=110100}}</small>
|}

== See also ==
* [[Hierarchical file system]]
* [[Unix directory structure]]
* [[Freedesktop.org#Base Directory Specification|XDG Base Directory Specification]]

== Notes ==
{{Reflist|group=NB}}

== References ==

{{Reflist|30em}}

== External links ==
* {{Official website}}
** [https://lists.freedesktop.org/postorius/lists/fhs.lists.freedesktop.org/ FHS Mailing List]
** [https://gitlab.freedesktop.org/FHS/ FHS repo]
** [https://refspecs.linuxfoundation.org/fhs.shtml Official website (2015–2025, historical)]
** [https://www.pathname.com/fhs/ Original FHS website (archival)]
* [https://www.freedesktop.org/software/systemd/man/devel/file-hierarchy.html systemd: file-hierarchy — File system hierarchy overview]
* [https://uapi-group.org/specifications/specs/linux_file_system_hierarchy/ UAPI Group Specifications: Linux File System Hierarchy]
* {{cite web |title=Objectroot |url=http://objectroot.org/ |url-status=usurped |archive-url=https://web.archive.org/web/20211016063611/http://objectroot.org/ |archive-date=16 October 2021}} A proposal for a new filesystem hierarchy, based on object-oriented design principles.
* {{cite web |title=Dotted Standard Filename Hierarchy |url=http://ftp.gwdg.de/pub/cLIeNUX/descriptive/DSFH.html |url-status=dead |archive-url=https://web.archive.org/web/20050508015157/http://ftp.gwdg.de/pub/cLIeNUX/descriptive/DSFH.html |archive-date=8 May 2005}} Yet another very different hierarchy (used in cLIeNUX).
* {{man|7|hier|Linux}}

{{Computer files}}

[[Category:Computer standards]]
[[Category:File system directories| ]]
[[Category:Linux]]
[[Category:System administration]]
[[Category:Unix file system technology]]