Sysadmins and anyone else writing administrative scripts should be intimately familiar with the following system directories.
Binaries (executables). Basic system programs and utilities (such as bash).
More system binaries.
Miscellaneous binaries local to the particular machine.
System binaries. Basic system administrative programs and utilities (such as fsck).
More system administrative programs and utilities.
Et cetera. Systemwide configuration scripts.
Of particular interest are the
(mounted filesystem table), and the
Boot scripts, on Red Hat and derivative distributions of Linux.
Documentation for installed packages.
The systemwide manpages.
Device directory. Entries (but not
mount points) for physical and virtual devices.
See Chapter 29,
Process directory. Contains information and statistics
about running processes and kernel parameters.
See Chapter 29,
Systemwide device directory. Contains information and statistics about device and device names. This is newly added to Linux with the 2.6.X kernels.
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.
In newer Linux distros, the preferred mount point for I/O devices, such as CD/DVD drives or USB flash drives.
Variable (changeable) system files. This is a catchall “scratchpad” directory for data generated while a Linux/UNIX machine is running.
Systemwide log files.
User mail spool.
Systemwide library files.
More systemwide library files.
System temporary files.
System boot directory. The kernel, module links, system map, and boot manager reside here.
Altering files in this directory may result in an unbootable system.
 Some early UNIX systems had a fast, small-capacity fixed
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
and the others on the slower drive, in
This likewise accounts for the split between