Changing Kernel Parameters on HP-UX

If you are installing an application on HP-UX (usually Database programs) and it requires specific kernel parameters, you can make adjustments using the kctune command.  Here’s an example of changing kernel parameters on HP-UX.

Change Kernel Parameters

For example, the requirement is to set semmns parameter to a value of 50000.
First, check the current running Value. You can confirm using the kctune command if the value can be change Immediately or at Next Boot.
You should also confirm here at that “Value on Next Boot” is the one you specifically set.

/# kctune -v semmns
Tunable             semmns
Description         Maximum number of semaphores
Module              pm_usync
Current Value       8192
Value at Next Boot  8192
Value at Last Boot  8192
Default Value       4096
Constraints         semmns >= 2
semmns <= 335534080
semmns >= semmni
semmns >= semume
Can Change          Immediately or at Next Boot

Now you can change the value using the following syntax:

/# kctune semmns=50000
/# kctune -v semmns
Tunable             semmns
Description         Maximum number of semaphores
Module              pm_usync
Current Value       50000
Value at Next Boot  50000
Value at Last Boot  8192
Default Value       4096
Constraints         semmns >= 2
semmns <= 335534080                     semmns >= semmni
semmns >= semume
Can Change          Immediately or at Next Boot

That’s it. Since the value is can be change Immediately, no further action is needed.


– masterkenneth

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