Miscellaneous binaries local to the particular machine.
/sbin
System binaries. Basic system administrative programs
and utilities (such as fsck).
/usr/sbin
More system administrative programs and utilities.
/etc
Et cetera. Systemwide configuration
scripts.
Of particular interest are the
/etc/fstab (filesystem table),
/etc/mtab
(mounted filesystem table), and the /etc/inittab
files.
/etc/rc.d
Boot scripts, on Red Hat and derivative distributions
of Linux.
/usr/share/doc
Documentation for installed packages.
/usr/man
The systemwide manpages.
/dev
Device directory. Entries (but not
mount points) for physical and virtual devices.
See Chapter 27.
/proc
Process directory. Contains information and statistics
about running processes and kernel parameters.
See Chapter 27.
/sys
Systemwide device directory. Contains information and
statistics about device and device names. This is newly
added to Linux with the 2.6.X kernels.
/mnt
Mount. Directory for mounting
hard drive partitions, such as /mnt/dos, and physical
devices. In newer Linux distros, the /media directory has taken
over as the preferred mount point for I/O devices.
/media
In newer Linux distros, the preferred mount point for
I/O devices, such as CD ROMs or USB flash drives.
/var
Variable (changeable) system
files. This is a catchall "scratchpad"
directory for data generated while a Linux/UNIX machine
is running.
/var/log
Systemwide log files.
/var/spool/mail
User mail spool.
/lib
Systemwide library files.
/usr/lib
More systemwide library files.
/tmp
System temporary files.
/boot
System boot directory. The kernel,
module links, system map, and boot manager reside here.
Warning
Altering files in this directory may result in an
unbootable system.
Some early UNIX systems had a fast, small-capacity fixed
disk (containing /,
the root partition), and a second drive which
was larger, but slower (containing /usr and other
partitions). The most frequently used programs and
utilities therefore resided on the small-but-fast
drive, in /bin,
and the others on the slower drive, in /usr/bin.
This likewise accounts for the split between
/sbin and
/usr/sbin,
/lib and /usr/lib, etc.