| / |
Primary hierarchy root and root directory of the entire file system hierarchy. |
| /bin |
Essential command binaries that need to be available in single user mode; for all users, e.g., cat, ls, cp. |
| /boot |
Boot loader files, e.g., kernels, initrd. |
| /dev |
Essential devices, e.g., /dev/null. |
| /etc |
Host-specific system-wide configuration files.There has been controversy over the meaning of the name itself. In early versions of the UNIX Implementation Document from Bell labs, /etc is referred to as the etcetera directory,[2] as this directory historically held everything that did not belong elsewhere (however, the FHS restricts /etc to static configuration files and may not contain binaries).[3] Since the publication of early documentation, the directory name has been re-explained in various ways. Recent interpretations include backronyms such as "Editable Text Configuration" or "Extended Tool Chest".[4] |
| /etc/opt |
Configuration files for add-on packages that are stored in /opt/. |
| /etc/sgml |
Configuration files, such as catalogs, for software that processes SGML. |
| /etc/X11 |
Configuration files for the X Window System, version 11. |
| /etc/xml |
Configuration files, such as catalogs, for software that processes XML. |
| /home |
Users' home directories, containing saved files, personal settings, etc. |
| /lib |
Libraries essential for the binaries in /bin/ and /sbin/. |
| /lib |
Alternate format essential libraries. Such directories are optional, but if they exist, they have some requirements. |
| /media |
Mount points for removable media such as CD-ROMs (appeared in FHS-2.3). |
| /mnt |
Temporarily mounted filesystems. |
| /opt |
Optional application software packages.[5] |
| /proc |
Virtual filesystem providing process and kernel information as files. In Linux, corresponds to a procfs mount. |
| /root |
Home directory for the root user. |
| /run |
Run-time variable data: Information about the running system since last boot, e.g., currently logged-in users and running daemons. |
| /sbin |
Essential system binaries, e.g., fsck, init, route. |
| /srv |
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. |
| /tmp |
Temporary files (see also /var/tmp). Often not preserved between system reboots, and may be severely size restricted. |
| /usr |
Secondary hierarchy for read-only user data; contains the majority of (multi-)user utilities and applications.[6] |
| /usr/bin |
Non-essential command binaries (not needed in single user mode); for all users. |
| /usr/include |
Standard include files. |
| /usr/lib |
Libraries for the binaries in /usr/bin/ and /usr/sbin/. |
| /usr/lib |
Alternate format libraries (optional). |
| /usr/local |
Tertiary hierarchy for local data, specific to this host. Typically has further subdirectories, e.g., bin/, lib/, share/.[7] |
| /usr/sbin |
Non-essential system binaries, e.g., daemons for various network-services. |
| /usr/share |
Architecture-independent (shared) data. |
| /usr/src |
Source code, e.g., the kernel source code with its header files. |
| /usr/X11R6 |
X Window System, Version 11, Release 6 (up to FHS-2.3, optional). |
| /var |
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. |
| /var/cache |
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. |
| /var/lib |
State information. Persistent data modified by programs as they run, e.g., databases, packaging system metadata, etc. |
| /var/lock |
Lock files. Files keeping track of resources currently in use. |
| /var/log |
Log files. Various logs. |
| /var/mail |
Users' mailboxes. |
| /var/opt |
Variable data from add-on packages that are stored in /opt/. |
| /var/run |
Run-time variable data. This directory contains system information data describing the system since it was booted.[8] In FHS 3.0, /var/run is replaced by /run; a system should either continue to provide a /var/run directory, or provide a symbolic link from /var/run to /run, for backwards compatibility.[9] |
| /var/spool |
Spool for tasks waiting to be processed, e.g., print queues and outgoing mail queue. |
| /var/spool/mail |
Deprecated location for users' mailboxes.[10] |
| /var/tmp |
Temporary files to be preserved between reboots. |