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The process of developing a standard filesystem hierarchy began in August 1993 with an effort to restructure the file and directory structure of Linux. The FSSTND, a filesystem hierarchy standard specific to the Linux operating system, was released on February 14, 1994. Subsequent revisions were released on October 9, 1994 and March 28, 1995. In early 1995, the goal of developing a more comprehensive version of FSSTND to address not only Linux, but other UNIX-like systems was adopted with the help of members of the BSD development community. As a result, a concerted effort was made to focus on issues that were general to UNIX-like systems. In recognition of this widening of scope, the name of the standard was changed to Filesystem Hierarchy Standard or FHS for short. Volunteers who have contributed extensively to this standard are listed at the end of this document. This standard represents a consensus view of those and other contributors. Thanks to Network Operations at the University of California at San Diego, and later to SourceForge, who allowed us to use their excellent mailing list servers during earlier phases of development.

Here are some of the guidelines that have been used in the development of this standard: Solve technical problems while limiting transitional difficulties. Make the specification reasonably stable. Gain the approval of distributors, developers, and other decision-makers in relevant development groups and encourage their participation. Provide a standard that is attractive to the implementors of different UNIX-like systems.

This document specifies a standard filesystem hierarchy for FHS filesystems by specifying the location of files and directories, and the contents of some system files. This standard has been designed to be used by system integrators, package developers, and system administrators in the construction and maintenance of FHS compliant filesystems. It is primarily intended to be a reference and is not a tutorial on how to manage a conforming filesystem hierarchy. The FHS grew out of earlier work on FSSTND, a filesystem organization standard for the Linux operating system. It builds on FSSTND to address interoperability issues not just in the Linux community but in a wider arena including 4.4BSD-based operating systems. It incorporates lessons learned in the BSD world and elsewhere about multi-architecture support and the demands of heterogeneous networking. Although this standard is more comprehensive than previous attempts at filesystem hierarchy standardization, periodic updates may become necessary as requirements change in relation to emerging technology. It is also possible that better solutions to the problems addressed here will be discovered so that our solutions will no longer be the best possible solutions. Supplementary drafts may be released in addition to periodic updates to this document. However, a specific goal is backwards compatibility from one release of this document to the next. Comments related to this standard are welcome. Any comments or suggestions for changes may be directed to the FHS mailing list, or filed as bugs, or both. Typographical or grammatical comments should be filed as bugs. The bugtracker is at http://bugs.linuxfoundation.org - use the category FHS. Before sending mail to the mailing list it is requested that you first glance at the mailing list archives to avoid excessive re-discussion of old topics. Questions about how to interpret items in this document may occasionally arise. If you have need for a clarification, please contact the FHS mailing list. Since this standard represents a consensus of many participants, it is important to make certain that any interpretation also represents their collective opinion. For this reason it may not be possible to provide an immediate response unless the inquiry has been the subject of previous discussion.

The developers of the FHS wish to thank the developers, system administrators, and users whose input was essential to this standard. We wish to thank each of the contributors who helped to write, compile, and compose this standard. The FHS Group also wishes to thank those Linux developers who supported the FSSTND, the predecessor to this standard. If they hadn't demonstrated that the FSSTND was beneficial, the FHS could never have evolved.

Brandon S. Allbery John A. Martin Mike Sangrey Keith Bostic Ian McCloghrie David H. Silber Drew Eckhardt Chris Metcalf Thomas Sippel-Dau Rik Faith Ian Murdock Theodore Ts'o Karl Goetz David C. Niemi Stephen Tweedie Stephen Harris Lennart Poettering Fred N. van Kempen Ian Jackson Daniel Quinlan Bernd Warken Andreas Jaeger Eric S. Raymond Mats Wichmann JeffLicquia RustyRussell ChristopherYeoh