HP-UX System Administrator's Guide: Overview

Kernel Tunables
Kernel tunables are settings that determine things like how many processes can
simultaneously be active or how much memory can be allocated for certain data
structures within the kernel. For more information on kernel tunables, what they are,
and how to adjust them, see the HP-UX System Administrator’s Guide: Configuration
Management.
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.
44 Major Components of HP-UX