HP-UX System Administrator's Guide: Overview

supported in HP-UX 11i version 3 and function as they
always have.
• persistent device special files reference their
corresponding devices based on a world-wide unique
identifier that is built into, or associated with, the
device. Because persistent device special files are not
dependent on specific hardware paths, they allow for
multiple hardware paths to be represented by a single
device special file. This opens up many new HP-UX
features in the areas of I/O performance, reliability,
and flexibility.
• Device special files for pseudodevices. The majority of
device special files are not directly associated with
actual hardware devices but are instead used to access
pseudodevices that allow HP-UX to introduce a
virtualization layer between processes and disk storage
(like those for LVM or VxVM), simulate hardware
devices like terminals (ptys), or provide useful
abstractions like /dev/null (a device file often
referred to as the "bit bucket", used to receive and
discard output that is not needed) There are many
pseudo-devices in HP-UX, used for a variety of
purposes. Most of these are described in the manpages
of Section 7 of the HP-UX Reference Manual.
/etc The /etc directory stores system-wide configuration files
including files required for:
• customizing boot and shutdown activities
• networking configuration
• configuring which file systems to mount
• defining users and groups
• defining logical volumes
The previous list is only partial. For compatibility reasons,
/etc also contains a number of symbolic links to commands
in other directories (commands that once resided in the
/etc directory).
/etc/opt/product
Some optional products, when added to a server, create
subdirectories under the directory /etc/opt to store
product specific configuration information.
/home The /home directory is the default location for the home
directories for user accounts. For example: If a user
“Thomas” with user name thomas is added to an HP-UX
46 Major Components of HP-UX