STLLUG - St. Louis Linux User Group
10/19/1995 : Filesystem Structure Standard Tutorial
Presenter: Matthew Feldt

Linux Filesystem Structure Standard

The official HTML version of the file system standard can be found at http://www.pathname.com/fhs/.

Describes the structure of the filesystem:: - Locations of files and directories
- Not how the data is written to disk

Why?: - To promote uniformity across distributions
- Simplfy development of new applications/features

Features:: - Distingishes between shareable and unshareable resources
- R/O /usr filesystem
- Well organized binary directories

/	(Root) Must contain all the files necessary to boot the machine single
/bin	Essential commands
/boot	Boot loader files and optionally kernels
/dev	Device files
/etc	Machine local config files
/home	Home directories
/lib	Shared libraries
/mnt	Temporary mount points
/proc	Process information pseudo-filesystem
/root	Home directory for root
/sbin	Essential system binaries
/tmp	Temporary files
/usr	Second major hierarchy
/var	Variable data (Third major hierarchy)

General rule:: If a user needs to execute it, put it in /bin
If only superuser or startup needs it, put it in /sbin
Required files:: arch, cat, chgrp, chmod, chown, cp, date, dd, df, dmesg, echo, ed, false, kill, ln, login, ls, mkdir, mknod, more, mount, mv, ps, pwd, rm, rmdir, sed, setserial, sh, stty, su, sync, true, umount, uname
All user-level recovery binaries should also be in /bin:: tar, cpio, gzip, gunzip, zcat
Some shells:: bash, sh (link to bash), tcsh, ash, zsh, pksh

Required files:: adjtime, csh.login, disktab, fdprm, fstab, gettydefs, group, inittab, issue, ld.so.conf, lilo.conf, magic, motd, mtab, mtools, passwd, profile, psdatabase, securetty, shells, syslog.conf, termcap, ttytype
exports, ftpusers, gateways, hosts, host.conf, hosts.equiv, hosts.lpd inetd.conf, networks, printcap, protocols, resolv.conf, rpc, services

libc.so.*, libm.so.*, ld.so, cpp (for compatability),

/lib/modules - kernel loadable modules (unspecified) organized by version

Ordanary users should not have /sbin (/usr/sbin) on their paths.

Required files:: clock, getty, init, update, mkswap, swapon, swapoff, telinit, fastboot, fasthalt, halt, reboot, shutdown, fdisk, fsck, fsck.*, mkfs, mkfs.*, badblocks, dumpe2fs, e2fsck, mke2fs, mklost+found, tune2fs, lilo, arp, ifconfig, route
Optional files:: static ln, static sync, ldconfig, kbdrate, ctrlaltdel

/X11R6	X11 R6
/X386	X11 R5
/bin	Most user commands
/dict	Word lists
/doc	Misc. documentation
/etc	Site-wide system configuration
/games	Games
/include	Header files
/info	Gnu info files
/lib	Libraries
/local	Local files
/man	Manual pages
/sbin	Non-vital system admin binaries
/share	Architecture-independent data
/src	Source code (e.g. linux kernel source)

The sybolic links may be present for compatibility: /usr/adm -> /var/adm
/usr/preserve -> /var/preserve
/usr/spool -> /var/spool
/usr/tmp -> /var/tmp

Example contents: User-level networking binaries: telnet, ftp, ncftp, ping
Shells: (links to) bash, sh, tcsh, perl, tcl
Text utilities etc.

All networking daemons: in.*

/adm	System administration data, obsolete, symlink to /var/log
/catman	Formatted man pages
/lib	Application state information
/local	Variable data from /usr/local
/lock	Lock files
/log	Log files
/named	DNS files
/nis	NIS files
/preserve	Saved editor states
/run	Files relevant to running processes (pid's)
/spool	Queued work, mail, cron, news
/tmp	Temporary files, (to keep /tmp small)

Last Modified: 9 December 1995
St. Louis Unix Users Group - Linux SIG