Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Reconfiguring the Kernel (HP-UX 11i Version 2)
Chapter 3 365
The Automatic backup Configuration
The system automatically maintains a saved configuration called
backup. Generally, any time you use the kernel configuration tools to
make a change to the currently running configuration, the previous
(pre-change) configuration is saved to backup. Therefore the backup
configuration is somewhat like the “undo” command in a word processor.
In these cases, if you load the backup configuration using kconfig -l
backup, it will reverse the last change you made to the currently running
configuration using the kernel configuration commands.
Some changes can be made to the currently running configuration by
calling kernel system calls directly. The backup configuration is not
updated when those changes are made.
There are cases in which you may not want this automatic backup
behavior. For example, if you have made an undesirable change and are
trying to fix it, you do not want the kernel configuration commands to
replace a good backup configuration with the one containing your
undesirable change. The -K option (Keep the existing backup) can be
given in any kernel configuration command to disable the automatic
update of the backup configuration. When making changes using kcweb,
you can turn off the “back up the current configuration before applying
change” checkbox to disable the automatic backup behavior.
When your system first boots, the backup configuration mirrors the
configuration that was in use before the reboot. You may not want this
replaced by the first kernel configuration change you make, especially
since the first kernel configuration change could be made by a startup
script before you even get a login prompt.
For this reason, the first configuration changes after a boot are handled
specially. Instead of automatically replacing the backup configuration,
the kernel configuration commands will ask you whether or not to do so.
1
They will continue to ask, each time you make a change, until the first
time you say “yes”. From that point on, until next boot, they will
automatically replace the backup configuration with each change as
described above.
1. If the command is being run noninteractively, such as from a
startup script, the answer is assumed to be “No” for kcmodule,
kctune, and kcdevice, and “Yes” for kconfig.