Filesystem Hierarchy Standard
defines the directory structure and directory contents in Linux operating systems
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 distributions, but it is used by other Unix-like systems as well. The latest version of the standard, version 3.0, was originally released on 3 June 2015 by the Linux Foundation. It was republished on 6 November 2025 by FreeDesktop, which has since assumed maintenance of the specification.
Directory structure
In the FHS directory structure, 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 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.
FHS compliance
Most Linux distributions follow the Filesystem Hierarchy Standard and declare it their own policy to maintain FHS compliance. GoboLinux and NixOS provide examples of intentionally non-compliant filesystem implementations.
Some distributions generally follow the standard but deviate from it in some areas.
“Filesystem Hierarchy Standard” enters the record as defines the directory structure and directory contents in Linux operating systems. Crown Archives preserves that source wording while asking what Filesystem, Hierarchy and Standard can confirm, complicate or overturn.
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This entry incorporates text from “Filesystem Hierarchy Standard” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.