topic Re: tunnable kernal parameter in Operating System - HP-UX

tunnable kernal parameter

navin — Fri, 18 Jul 2008 20:01:19 GMT

Hello,
I need to bring down the dbc_max_pctr to 25 from 50
Can i do it in running system...as below

kctune dbc_max_pct = 25

i do want the system to be restarted
Thanks in advance

Re: tunnable kernal parameter

James R. Ferguson — Fri, 18 Jul 2008 20:37:57 GMT

Hi Navin:

Yes, the 'dbc_max_pct' is dynamically tunable on 11.23 and later. Your syntax is correct.

Regards!

...JRF...

Re: tunnable kernal parameter

David Bellamy — Fri, 18 Jul 2008 20:49:31 GMT

navin: since you did not tell us what OS you are using I'm going to assume that it is HPUX 11.23 and yes you can use kctune to change that parameter on a running system without a reboot.

Re: tunnable kernal parameter

Asif Sharif — Sat, 19 Jul 2008 05:54:41 GMT

This can be easily done through SAM also.

SAM->Kernel Configuration->Configurable Parameters->
Select the parameter and double click. Change value to desired value e.g.(25).

or

do it with command.

#kctune dbc_max_pct = 25

it will show you the output like this.

* The automatic 'backup' configuration has been updated.
* The requested changes have been applied to the currently running system.
Tunable Value Expression Changes

Regards,
Asif Sharif

Re: tunnable kernal parameter

Rasheed Tamton — Sat, 19 Jul 2008 07:06:31 GMT

Hi Navin,

If your OS is 11.23 you can change it online (without a reboot)

kctune -v dbc_max_pct
(Check the last line of the result, can change immediately means dynamic)

or
if you want to be more satisfied, then use
kcweb -t
enter Tunables
scroll down until you see the dbc_max_pct. Check the Tuning Capability column to know whether it is static or Dynamic. If you press "d" it will show all the dynamic tunables.

Regards,
Rasheed Tamton.

Re: tunnable kernal parameter

Jeeshan — Sun, 20 Jul 2008 02:53:19 GMT

depends upon your OS version.

in 11iv1, you need restart but from 11.23, its dynamic. no need restart.