HP-UX System Administrator's Guide: Overview HP-UX 11i v3 (B3921-90011, September 2010)

NOTE: Some kernel tunables have their values set at boot time and cannot be changed without
rebooting. Other kernel tunables can be “tuned” (have their settings adjusted) while the kernel
is running.
The HP-UX Directory Structure
HP-UX 11i, like all versions of UNIX and many other operating systems, is based on a hierarchical
directory structure that contains all of the operating system directories and files, as well as all
user and application files.
The directory structure can be contained entirely within a single file system, but it is usually
comprised of multiple file systems that attach to the root file system at special directories known
as mount points.
The top of the tree is known as the root directory and is represented by the directory path “/”.
All other directories and files reside under the root directory. Each layer of the directory tree is
represented in directory path names (pathnames) by adding its name to the end of the path, with
each layer separated by a slash character (“/”). See the following examples:
Example 3-1 Directory Path Name Nomenclature
/
The root directory
/usr The usr directory within the root directory
/home/guest27 The guest27 account within the home directory within
the root directory
/usr/share/man/man1.Z/cat.1 cat.1 is a file within the man1.Z directory, within the
man directory, within the share directory, within the usr
directory, within the root directory (/). It just happens to
be the source file for the cat(1) manpage.
Figure 3-1 Directory Tree Example
share vuelibbinadm
man9.Zman7.Z
man5.Zman4.Zman3.Zman2.Z
man1M.Z
cat.1
man1.Z
man
/
Key HP-UX Directories
This section describes many of the key directories in the HP-UX directory structure and what
they are used for.
/dev
Contains device special files. Though they appear in the directory tree
like regular disk files, device special files are associated with physical
devices or pseudodevices. They are portals to the devices and device
drivers they are associated with.
Device special files are written to or read from by software
applications or operating system components to access data on the
40 Major Components of HP-UX