HP-UX System Administrator's Guide: Configuration Management

installed Initial installation
last_install Created by last OS install
# kconfig -w
* The currently running configuration was created on Fri Dec 15
17:39:39 2006 by root as a copy of 'last_install'.
* It was last saved on Fri Dec 15 17:45:11 2006 by root.
* It was last modified on Fri Dec 15 18:04:58 2006 by root.
Then, she saves the new kernel configuration under the name good, so that she can go
back to it, if needed. She gives it a title to help recognize it later.
# kconfig -C "Good configuration for Prophet" -s good
* The currently running configuration has been saved as 'good'.
# kconfig -t good "Good configuration for Prophet"
* The title of the configuration 'good' has been set to "Good
configuration for Prophet".
After some time, one of her users asks her to increase the size of the buffer cache, hoping
to speed up the application. She complies — after all, it doesn’t need a reboot, so she
can do it without disturbing anyone. Since it’s the first change after a boot, the system
asks whether to make automatic backups.
# kctune -C "Bigger file cache for better performance" filecache_max=20%
==> Update the automatic 'backup' configuration first? yes
* The automatic 'backup' configuration has been updated.
* Future operations will update the backup without prompting.
* The requested changes have been applied to the currently
running configuration.
Tunable Value Expression Changes
filecache_max (before) 1017118720 Default Imm (auto disabled)
(now) 406847488 20%
It’s a good thing she said yes. The larger buffer cache actually slowed things down —
but all she has to do is restore the automatic backup.
# kconfig -C "Putting file cache back; performance was worse." -l backup
* The automatic 'backup' configuration has been updated.
* The requested changes have been applied to the currently
running configuration.
* The automatic 'backup' configuration has been loaded and is now
in use.
# kctune filecache_max
Tunable Value Expression Changes
filecache_max 1017118720 Default Auto
While Susan is on vacation, her colleague, Fred, decides to use the machine for billing
software during the night. This software needs to execute code on the stack (a security
risk), so he enables that behavior (which is prohibited by default). No reboot is needed
to do so.
# kctune -d executable_stack
Tunable Value Expression Changes
Description
executable_stack 0 Default Immed
Enables execution of code on a stack (0 = no, 1 = yes, 2 = yes but warn)
204 Configuring the Kernel