Filesystem Hierarchy Standard
The Filesystem Hierarchy Standard (FHS) defines the main directories and their contents in Linux and other Unix-like computer operating systems.All files and directories appear under the root directory /, even if stored on different physical devices. Directories defined by the FHS include:
- /bin/ Essential command binaries for all users (e.g., cat, ls, cp)
- /boot/ Boot loader files (e.g., kernelss, initrd)
- /dev/ Essential devices (e.g., //dev/null)
- /etc/ Host-specific system-wide configuration files
- /etc/opt/ Configuration files for /opt/
- /etc/X11/ (optional) Configuration files for the X Window System
- /etc/sgml/ (optional) Configuration files for SGML
- /etc/xml/ (optional) Configuration files for XML
- /home/ (optional) Users' home directories
- /lib/ Libraries essential for the binaries in /bin/ and /sbin/
- /mnt/ Temporarily mounted filesystems
- /media/ Mountpoints for removable media such as CD-Roms (appeared in FHS-2.3)
- /opt/ Static application software packages
- /proc/ Virtual filesystem documenting kernel status, mostly text files (e.g., uptime, network)
- /root/ (optional) Home directory for the root user
- /sbin/ Essential binaries for root (e.g., init, route, ifup)
- /tmp/ (optional) Temporary files
- /usr/ Secondary hierarchy for shareable, read-only data
- /usr/bin/, /usr/lib/, /usr/sbin/ Same as for top-level hierarchy
- /usr/include/ Standard include files
- /usr/share/ Architecture-independent data
- /usr/src/ (optional) Source code
- /usr/X11R6/ (optional) X Window System, Version 11 Release 6
- /usr/local/ Tertiary hierarchy for local data installed by the system administrator
- /var/ Variable files, such as logs and temporary files