Difference between revisions of "Funtoo Filesystem Hierarchy"

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(Split out the /usr filesystem into its own page.)
(Split out the /var filesystem onto its own page.)
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= [[The /usr Hierarchy]] =
 
= [[The /usr Hierarchy]] =
  
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= The /var Hierarchy =
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= [[The /var Hierarchy]] =
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/var contains variable data files. This includes spool directories and files, administrative and logging data, and transient and temporary files.
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Some portions of /var are not shareable between different systems. For instance, /var/log, /var/lock, and /var/run. Other portions may be shared, notably /var/mail, /var/cache/man, /var/cache/fonts, and /var/spool/news.
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/var is specified here in order to make it possible to mount /usr read-only. Everything that once went into /usr that is written to during system operation (as opposed to installation and software maintenance) must be in /var.
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If /var cannot be made a separate partition, it is often preferable to move /var out of the root partition and into the /usr partition. (This is sometimes done to reduce the size of the root partition or when space runs low in the root partition.) However, /var must not be linked to /usr because this makes separation of /usr and /var more difficult and is likely to create a naming conflict. Instead, link /var to /usr/var.
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Applications must generally not add directories to the top level of /var. Such directories should only be added if they have some system-wide implication, and in consultation with the FHS mailing list.
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== Requirements ==
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The following directories, or symbolic links to directories, are required in /var.
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Directory Description
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cache Application cache data
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lib Variable state information
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local Variable data for /usr/local
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lock Lock files
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log Log files and directories
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opt Variable data for /opt
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run Data relevant to running processes
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spool Application spool data
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tmp Temporary files preserved between system reboots
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Several directories are `reserved' in the sense that they must not be used arbitrarily by some new application, since they would conflict with historical and/or local practice. They are:
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    /var/backups
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    /var/cron
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    /var/msgs
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    /var/preserve
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== Specific Options ==
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The following directories, or symbolic links to directories, must be in /var, if the corresponding subsystem is installed:
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Directory Description
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account Process accounting logs (optional)
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crash System crash dumps (optional)
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games Variable game data (optional)
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mail User mailbox files (optional)
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yp Network Information Service (NIS) database files (optional)
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== /var/account : Process accounting logs (optional) ==
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This directory holds the current active process accounting log and the composite process usage data (as used in some UNIX-like systems by lastcomm and sa).
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== /var/cache : Application cache data ==
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/var/cache is intended for cached data from applications. Such data is locally generated as a result of time-consuming I/O or calculation. The application must be able to regenerate or restore the data. Unlike /var/spool, the cached files can be deleted without data loss. The data must remain valid between invocations of the application and rebooting the system.
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Files located under /var/cache may be expired in an application specific manner, by the system administrator, or both. The application must always be able to recover from manual deletion of these files (generally because of a disk space shortage). No other requirements are made on the data format of the cache directories.
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Tip Rationale
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The existence of a separate directory for cached data allows system administrators to set different disk and backup policies from other directories in /var.
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=== Specific Options ===
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Directory Description
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fonts Locally-generated fonts (optional)
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man Locally-formatted manual pages (optional)
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www WWW proxy or cache data (optional)
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<package> Package specific cache data (optional)
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=== /var/cache/fonts : Locally-generated fonts (optional) ===
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The directory /var/cache/fonts should be used to store any dynamically-created fonts. In particular, all of the fonts which are automatically generated by mktexpk must be located in appropriately-named subdirectories of /var/cache/fonts. <ref>This standard does not currently incorporate the TeX Directory Structure (a document that describes the layout TeX files and directories), but it may be useful reading. It is located at [ftp://ctan.tug.org/tex/]</ref>
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==== Specific Options ====
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Other dynamically created fonts may also be placed in this tree, under appropriately-named subdirectories of /var/cache/fonts.
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=== /var/cache/man : Locally-formatted manual pages (optional) ===
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This directory provides a standard location for sites that provide a read-only /usr partition, but wish to allow caching of locally-formatted man pages. Sites that mount /usr as writable (e.g., single-user installations) may choose not to use /var/cache/man and may write formatted man pages into the cat<section> directories in /usr/share/man directly. We recommend that most sites use one of the following options instead:
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    *
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      Preformat all manual pages alongside the unformatted versions.
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    *
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      Allow no caching of formatted man pages, and require formatting to be done each time a man page is brought up.
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    *
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      Allow local caching of formatted man pages in /var/cache/man.
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The structure of /var/cache/man needs to reflect both the fact of multiple man page hierarchies and the possibility of multiple language support.
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Given an unformatted manual page that normally appears in <path>/man/<locale>/man<section>, the directory to place formatted man pages in is /var/cache/man/<catpath>/<locale>/cat<section>, where <catpath> is derived from <path> by removing any leading usr and/or trailing share pathname components. (Note that the <locale> component may be missing.) <ref>For example, /usr/share/man/man1/ls.1 is formatted into /var/cache/man/cat1/ls.1, and /usr/X11R6/man/<locale>/man3/XtClass.3x into /var/cache/man/X11R6/<locale>/cat3/XtClass.3x.</ref>
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Man pages written to /var/cache/man may eventually be transferred to the appropriate preformatted directories in the source man hierarchy or expired; likewise formatted man pages in the source man hierarchy may be expired if they are not accessed for a period of time.
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If preformatted manual pages come with a system on read-only media (a CD-ROM, for instance), they must be installed in the source man hierarchy (e.g. /usr/share/man/cat<section>). /var/cache/man is reserved as a writable cache for formatted manual pages.
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Tip Rationale
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Release 1.2 of the standard specified /var/catman for this hierarchy. The path has been moved under /var/cache to better reflect the dynamic nature of the formatted man pages. The directory name has been changed to man to allow for enhancing the hierarchy to include post-processed formats other than "cat", such as PostScript, HTML, or DVI.
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== /var/crash : System crash dumps (optional) ==
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This directory holds system crash dumps. As of the date of this release of the standard, system crash dumps were not supported under Linux but may be supported by other systems which may comply with the FHS.
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== /var/games : Variable game data (optional) ==
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Any variable data relating to games in /usr should be placed here. /var/games should hold the variable data previously found in /usr; static data, such as help text, level descriptions, and so on, must remain elsewhere, such as /usr/share/games.
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Tip Rationale
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/var/games has been given a hierarchy of its own, rather than leaving it merged in with the old /var/lib as in release 1.2. The separation allows local control of backup strategies, permissions, and disk usage, as well as allowing inter-host sharing and reducing clutter in /var/lib. Additionally, /var/games is the path traditionally used by BSD.
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== /var/lib : Variable state information ==
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This hierarchy holds state information pertaining to an application or the system. State information is data that programs modify while they run, and that pertains to one specific host. Users must never need to modify files in /var/lib to configure a package's operation.
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State information is generally used to preserve the condition of an application (or a group of inter-related applications) between invocations and between different instances of the same application. State information should generally remain valid after a reboot, should not be logging output, and should not be spooled data.
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An application (or a group of inter-related applications) must use a subdirectory of /var/lib for its data. There is one required subdirectory, /var/lib/misc, which is intended for state files that don't need a subdirectory; the other subdirectories should only be present if the application in question is included in the distribution. <ref>An important difference between this version of this standard and previous ones is that applications are now required to use a subdirectory of /var/lib.</ref>
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/var/lib/<name> is the location that must be used for all distribution packaging support. Different distributions may use different names, of course.
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=== Requirements ===
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The following directories, or symbolic links to directories, are required in /var/lib:
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Directory Description
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misc Miscellaneous state data
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=== Specific Options ===
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The following directories, or symbolic links to directories, must be in /var/lib, if the corresponding subsystem is installed:
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Directory Description
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<editor> Editor backup files and state (optional)
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<pkgtool> Packaging support files (optional)
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<package> State data for packages and subsystems (optional)
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hwclock State directory for hwclock (optional)
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xdm X display manager variable data (optional)
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=== /var/lib/<editor> : Editor backup files and state (optional) ===
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These directories contain saved files generated by any unexpected termination of an editor (e.g., elvis, jove, nvi).
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Other editors may not require a directory for crash-recovery files, but may require a well-defined place to store other information while the editor is running. This information should be stored in a subdirectory under /var/lib (for example, GNU Emacs would place lock files in /var/lib/emacs/lock).
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Future editors may require additional state information beyond crash-recovery files and lock files — this information should also be placed under /var/lib/<editor>.
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Tip Rationale
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Previous Linux releases, as well as all commercial vendors, use /var/preserve for vi or its clones. However, each editor uses its own format for these crash-recovery files, so a separate directory is needed for each editor.
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Editor-specific lock files are usually quite different from the device or resource lock files that are stored in /var/lock and, hence, are stored under /var/lib.
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=== /var/lib/hwclock : State directory for hwclock (optional) ===
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This directory contains the file /var/lib/hwclock/adjtime.
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Tip Rationale
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In FHS 2.1, this file was /etc/adjtime, but as hwclock updates it, that was obviously incorrect.
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=== /var/lib/misc : Miscellaneous variable data ===
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This directory contains variable data not placed in a subdirectory in /var/lib. An attempt should be made to use relatively unique names in this directory to avoid namespace conflicts. <ref>This hierarchy should contain files stored in /var/db in current BSD releases. These include locate.database and mountdtab, and the kernel symbol database(s).</ref>
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== /var/lock : Lock files ==
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Lock files should be stored within the /var/lock directory structure.
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Lock files for devices and other resources shared by multiple applications, such as the serial device lock files that were originally found in either /usr/spool/locks or /usr/spool/uucp, must now be stored in /var/lock. The naming convention which must be used is "LCK.." followed by the base name of the device. For example, to lock /dev/ttyS0 the file "LCK..ttyS0" would be created. <ref>Then, anything wishing to use /dev/ttyS0 can read the lock file and act accordingly (all locks in /var/lock should be world-readable).</ref>
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The format used for the contents of such lock files must be the HDB UUCP lock file format. The HDB format is to store the process identifier (PID) as a ten byte ASCII decimal number, with a trailing newline. For example, if process 1230 holds a lock file, it would contain the eleven characters: space, space, space, space, space, space, one, two, three, zero, and newline.
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== /var/log : Log files and directories ==
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This directory contains miscellaneous log files. Most logs must be written to this directory or an appropriate subdirectory.
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=== Specific Options ===
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The following files, or symbolic links to files, must be in /var/log, if the corresponding subsystem is installed:
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File Description
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lastlog record of last login of each user
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messages system messages from syslogd
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wtmp record of all logins and logouts
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== /var/mail : User mailbox files (optional) ==
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The mail spool must be accessible through /var/mail and the mail spool files must take the form <username>. <ref>Note that /var/mail may be a symbolic link to another directory.</ref>
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User mailbox files in this location must be stored in the standard UNIX mailbox format.
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Tip Rationale
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The logical location for this directory was changed from /var/spool/mail in order to bring FHS in-line with nearly every UNIX implementation. This change is important for inter-operability since a single /var/mail is often shared between multiple hosts and multiple UNIX implementations (despite NFS locking issues).
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It is important to note that there is no requirement to physically move the mail spool to this location. However, programs and header files must be changed to use /var/mail.
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== /var/opt : Variable data for /opt ==
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Variable data of the packages in /opt must be installed in /var/opt/<subdir>, where <subdir> is the name of the subtree in /opt where the static data from an add-on software package is stored, except where superseded by another file in /etc. No structure is imposed on the internal arrangement of /var/opt/<subdir>.
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Tip Rationale
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Refer to the rationale for /opt.
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== /var/run : Run-time variable data ==
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This directory contains system information data describing the system since it was booted. Files under this directory must be cleared (removed or truncated as appropriate) at the beginning of the boot process. Programs may have a subdirectory of /var/run; this is encouraged for programs that use more than one run-time file. <ref>/var/run should be unwritable for unprivileged users (root or users running daemons); it is a major security problem if any user can write in this directory.</ref> Process identifier (PID) files, which were originally placed in /etc, must be placed in /var/run. The naming convention for PID files is <program-name>.pid. For example, the crond PID file is named /var/run/crond.pid.
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=== Requirements ===
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The internal format of PID files remains unchanged. The file must consist of the process identifier in ASCII-encoded decimal, followed by a newline character. For example, if crond was process number 25, /var/run/crond.pid would contain three characters: two, five, and newline.
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Programs that read PID files should be somewhat flexible in what they accept; i.e., they should ignore extra whitespace, leading zeroes, absence of the trailing newline, or additional lines in the PID file. Programs that create PID files should use the simple specification located in the above paragraph.
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The utmp file, which stores information about who is currently using the system, is located in this directory.
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System programs that maintain transient UNIX-domain sockets must place them in this directory.
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== /var/spool : Application spool data ==
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/var/spool contains data which is awaiting some kind of later processing. Data in /var/spool represents work to be done in the future (by a program, user, or administrator); often data is deleted after it has been processed. <ref>UUCP lock files must be placed in /var/lock. See the above section on /var/lock.</ref>
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=== Specific Options ===
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The following directories, or symbolic links to directories, must be in /var/spool, if the corresponding subsystem is installed:
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Directory Description
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lpd Printer spool directory (optional)
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mqueue Outgoing mail queue (optional)
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news News spool directory (optional)
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rwho Rwhod files (optional)
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uucp Spool directory for UUCP (optional)
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=== /var/spool/lpd : Line-printer daemon print queues (optional) ===
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The lock file for lpd, lpd.lock, must be placed in /var/spool/lpd. It is suggested that the lock file for each printer be placed in the spool directory for that specific printer and named lock.
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==== Specific Options ====
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Directory Description
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printer Spools for a specific printer (optional)
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=== /var/spool/rwho : Rwhod files (optional) ===
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This directory holds the rwhod information for other systems on the local net.
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Tip Rationale
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Some BSD releases use /var/rwho for this data; given its historical location in /var/spool on other systems and its approximate fit to the definition of `spooled' data, this location was deemed more appropriate.
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== /var/tmp : Temporary files preserved between system reboots ==
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The /var/tmp directory is made available for programs that require temporary files or directories that are preserved between system reboots. Therefore, data stored in /var/tmp is more persistent than data in /tmp.
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Files and directories located in /var/tmp must not be deleted when the system is booted. Although data stored in /var/tmp is typically deleted in a site-specific manner, it is recommended that deletions occur at a less frequent interval than /tmp.
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== /var/yp : Network Information Service (NIS) database files (optional) ==
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Variable data for the Network Information Service (NIS), formerly known as the Sun Yellow Pages (YP), must be placed in this directory.
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Tip Rationale
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/var/yp is the standard directory for NIS (YP) data and is almost exclusively used in NIS documentation and systems. <ref>NIS should not be confused with Sun NIS+, which uses a different directory, /var/nis.</ref>
+
  
 
= Operating System Specific Annex =
 
= Operating System Specific Annex =

Revision as of 05:11, 7 November 2010

The Funtoo Filesystem Hierarchy is derived from the Filesystem Hierarchy Standard, and updated to address Funtoo Linux and Gentoo Linux-specific conventions.

Contents

License and Copyright

In accordance with the upstream documentation, this document is distributed under the following terms:

Copyright © 1994-2004 Daniel Quinlan

Copyright © 2001-2004 Paul 'Rusty' Russell

Copyright © 2003-2004 Christopher Yeoh

Copyright © 2010 Funtoo Technologies


Permission is granted to make and distribute verbatim copies of this standard provided the copyright and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this standard under the conditions for verbatim copying, provided also that the title page is labeled as modified including a reference to the original standard, provided that information on retrieving the original standard is included, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this standard into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the copyright holder.

Introduction

This standard enables:

  • Software to predict the location of installed files and directories, and
  • Users to predict the location of installed files and directories.

We do this by:

  • Specifying guiding principles for each area of the filesystem,
  • Specifying the minimum files and directories required,
  • Enumerating exceptions to the principles, and
  • Enumerating specific cases where there has been historical conflict.

The FHS document is used by:

  • Independent software suppliers to create applications which are FHS compliant, and work with distributions which are FHS complaint,
  • OS creators to provide systems which are FHS compliant, and
  • Users to understand and maintain the FHS compliance of a system.

The FHS document has a limited scope:

  • Local placement of local files is a local issue, so FHS does not attempt to usurp system administrators.
  • FHS addresses issues where file placements need to be coordinated between multiple parties such as local sites, distributions, applications, documentation, etc.

The Filesystem

This standard assumes that the operating system underlying an FHS-compliant file system supports the same basic security features found in most UNIX filesystems.

It is possible to define two independent distinctions among files: shareable vs. unshareable and variable vs. static. In general, files that differ in either of these respects should be located in different directories. This makes it easy to store files with different usage characteristics on different filesystems.

"Shareable" files are those that can be stored on one host and used on others. "Unshareable" files are those that are not shareable. For example, the files in user home directories are shareable whereas device lock files are not.

"Static" files include binaries, libraries, documentation files and other files that do not change without system administrator intervention. "Variable" files are files that are not static.

Tip Rationale


Shareable files can be stored on one host and used on several others. Typically, however, not all files in the filesystem hierarchy are shareable and so each system has local storage containing at least its unshareable files. It is convenient if all the files a system requires that are stored on a foreign host can be made available by mounting one or a few directories from the foreign host.

Static and variable files should be segregated because static files, unlike variable files, can be stored on read-only media and do not need to be backed up on the same schedule as variable files.

Historical UNIX-like filesystem hierarchies contained both static and variable files under both /usr and /etc. In order to realize the advantages mentioned above, the /var hierarchy was created and all variable files were transferred from /usr to /var. Consequently /usr can now be mounted read-only (if it is a separate filesystem). Variable files have been transferred from /etc to /var over a longer period as technology has permitted.

Here is an example of a FHS-compliant system. (Other FHS-compliant layouts are possible.)

shareable unshareable
static /usr /etc
/opt /boot
variable /var/mail /var/run
/var/spool/news /var/lock

The Root Filesystem

The /usr Hierarchy

The /var Hierarchy

Operating System Specific Annex

This section is for additional requirements and recommendations that only apply to a specific operating system. The material in this section should never conflict with the base standard.

Linux

This is the annex for the Linux operating system.

/ : Root directory

On Linux systems, if the kernel is located in /, we recommend using the names vmlinux or vmlinuz, which have been used in recent Linux kernel source packages.

/bin : Essential user command binaries (for use by all users)

Linux systems which require them place these additional files into /bin: 

   *

     setserial

/dev : Devices and special files

The following devices must exist under /dev.

/dev/null 

   All data written to this device is discarded. A read from this device will return an EOF condition.

/dev/zero 

   This device is a source of zeroed out data. All data written to this device is discarded. A read from this device will return as many bytes containing the value zero as was requested.

/dev/tty 

   This device is a synonym for the controlling terminal of a process. Once this device is opened, all reads and writes will behave as if the actual controlling terminal device had been opened.

Tip Rationale


Previous versions of the FHS had stricter requirements for /dev. Other devices may also exist in /dev. Device names may exist as symbolic links to other device nodes located in /dev or subdirectories of /dev. There is no requirement concerning major/minor number values.

/etc : Host-specific system configuration

Linux systems which require them place these additional files into /etc. 

   *

     lilo.conf

/lib64 and /lib32 : 64/32-bit libraries (architecture dependent)

The 64-bit architectures PPC64, s390x, sparc64 and AMD64 must place 64-bit libraries in /lib64, and 32-bit (or 31-bit on s390) libraries in /lib.

The 64-bit architecture IA64 must place 64-bit libraries in /lib.

Tip Rationale


This is a refinement of the general rules for /lib<qual> and /usr/lib<qual>. The architectures PPC64, s390x, sparc64 and AMD64 support support both 32-bit (for s390 more precise 31-bit) and 64-bit programs. Using lib for 32-bit binaries allows existing binaries from the 32-bit systems to work without any changes: such binaries are expected to be numerous. IA-64 uses a different scheme, reflecting the deprecation of 32-bit binaries (and hence libraries) on that architecture.

/proc : Kernel and process information virtual filesystem

The proc filesystem is the de-facto standard Linux method for handling process and system information, rather than /dev/kmem and other similar methods. We strongly encourage this for the storage and retrieval of process information as well as other kernel and memory information.

/sbin : Essential system binaries

Linux systems place these additional files into /sbin. 

   *

     Second extended filesystem commands (optional):

         o

           badblocks
         o

           dumpe2fs
         o

           e2fsck
         o

           mke2fs
         o

           mklost+found
         o

           tune2fs
   *

     Boot-loader map installer (optional):

         o

           lilo

Optional files for /sbin: 

   *

     Static binaries:

         o

           ldconfig
         o

           sln
         o

           ssync

     Static ln (sln) and static sync (ssync) are useful when things go wrong. The primary use of sln (to repair incorrect symlinks in /lib after a poorly orchestrated upgrade) is no longer a major concern now that the ldconfig program (usually located in /usr/sbin) exists and can act as a guiding hand in upgrading the dynamic libraries. Static sync is useful in some emergency situations. Note that these need not be statically linked versions of the standard ln and sync, but may be.

     The ldconfig binary is optional for /sbin since a site may choose to run ldconfig at boot time, rather than only when upgrading the shared libraries. (It's not clear whether or not it is advantageous to run ldconfig on each boot.) Even so, some people like ldconfig around for the following (all too common) situation:

        1.

           I've just removed /lib/<file>.
        2.

           I can't find out the name of the library because ls is dynamically linked, I'm using a shell that doesn't have ls built-in, and I don't know about using "echo *" as a replacement.
        3.

           I have a static sln, but I don't know what to call the link.
   *

     Miscellaneous:

         o

           ctrlaltdel
         o

           kbdrate

     So as to cope with the fact that some keyboards come up with such a high repeat rate as to be unusable, kbdrate may be installed in /sbin on some systems.

     Since the default action in the kernel for the Ctrl-Alt-Del key combination is an instant hard reboot, it is generally advisable to disable the behavior before mounting the root filesystem in read-write mode. Some init suites are able to disable Ctrl-Alt-Del, but others may require the ctrlaltdel program, which may be installed in /sbin on those systems.

/usr/include : Header files included by C programs

These symbolic links are required if a C or C++ compiler is installed and only for systems not based on glibc. 

   /usr/include/asm -> /usr/src/linux/include/asm-<arch>
   /usr/include/linux -> /usr/src/linux/include/linux

/usr/src : Source code

For systems based on glibc, there are no specific guidelines for this directory. For systems based on Linux libc revisions prior to glibc, the following guidelines and rationale apply:

The only source code that should be placed in a specific location is the Linux kernel source code. It is located in /usr/src/linux.

If a C or C++ compiler is installed, but the complete Linux kernel source code is not installed, then the include files from the kernel source code must be located in these directories: 

   /usr/src/linux/include/asm-<arch>
   /usr/src/linux/include/linux

<arch> is the name of the system architecture.

Note Note


/usr/src/linux may be a symbolic link to a kernel source code tree.

Tip Rationale


It is important that the kernel include files be located in /usr/src/linux and not in /usr/include so there are no problems when system administrators upgrade their kernel version for the first time.

/var/spool/cron : cron and at jobs

This directory contains the variable data for the cron and at programs.

Appendix

Background of the FHS

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.

General Guidelines

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.

Scope

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 editor (Daniel Quinlan <quinlan@pathname.com>) or the FHS mailing list. Typographical or grammatical comments should be directed to the FHS editor.

Before sending mail to the mailing list it is requested that you first contact the FHS editor in order 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 editor. 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.

Acknowledgments

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.

Original Contributors

Several people contributed to the filesystem hierarchy standard used as a basis for this document. Those people include:

Notes

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