topic Re: kernel parameter in Operating System - HP-UX

kernel parameter

S.S. — Wed, 20 Jan 2010 03:52:33 GMT

Hi,

Current executable_stack is 1 and i want to change this to 0.

This is a static parameter. Does it require reboot ?

My OS version is HP-UX 11.11
model is rp3440

I didn't find the kctune utility. Can we do it by using kmtune?
Please give me the steps to change the executable_stack parameter to 0 by using kmtune.

Re: kernel parameter

Kapil Jha — Wed, 20 Jan 2010 04:05:36 GMT

Every static parameter require a reboot!!
dynamic not.

if u not sure do it with SAM pretty simple.

BR,
Kapil+

Re: kernel parameter

Kapil Jha — Wed, 20 Jan 2010 04:12:41 GMT

i forgt...

kmtune -s executable_stack=0

BR,
Kapil+

Re: kernel parameter

Johnson Punniyalingam — Wed, 20 Jan 2010 05:38:05 GMT

>>This is a static parameter. Does it require reboot ?<<<

Yes, It require reboot (all Static parameter require reboot to take effect)

better if you could you "SAM" -its easy and simple to use.

one more important thing if you could "Ignite backup" for OS before you perform the "kernel parameter" change to in the safer side

Re: kernel parameter

Sagar Sirdesai — Wed, 20 Jan 2010 06:51:10 GMT

You have to recreate the kernel and then reboot.

Make a copy /stand/vmunix and /stand/system before executing the below steps

Below are command line steps
1)cd /stand/build ; rm -r *
2)/usr/lbin/sysadm/system_prep -v -s /stand/build/system
3)Change the required Kernel parameters
kmtune -s executable_stack=0 -S /stand/build/system
4)cp /stand/build/system /stand/system
5)mk_kernel
6)km_update
7)cd / ; shutdown -ry 0 now

Sagar

Re: kernel parameter

Johnson Punniyalingam — Wed, 20 Jan 2010 06:53:25 GMT

"SAM" -its easy and simple to use

Because "SAM" will automatically backup your current kernal and compile a new kernal and the Server will automatically reboot

Re: kernel parameter

AVV — Wed, 20 Jan 2010 07:43:13 GMT

The steps given by Sagar looks good.

If you are confident over command line go thru that and you will know what happens when you do the tuning. SAM does the same.Remember, all static parameters do need reboot but not for dynamic.Dynamic parameters can be changed as required.
==============
Do a copy of /stand/vmunix also incase you face any issue to boot with the new kernel,can be booted from the copied one.

Eg. cp -p /stand/vmunix /stand/vmunix_date

1)cd /stand/build ; rm -r *
2)/usr/lbin/sysadm/system_prep -v -s /stand/build/system
3)Change the required Kernel parameters
kmtune -s executable_stack=0 -S /stand/build/system
4)cp /stand/build/system /stand/system
5)mk_kernel
6)km_update
7)cd / ; shutdown -ry 0 now

Re: kernel parameter

S.S. — Wed, 20 Jan 2010 09:01:56 GMT

Actually Oracle10g is running on the machine. May i know, if we reset the value of executable_stack parameter to 0, will there is any impact ?

I have send an email to my TeamLead for the schedule of this to reset the parameter.

Thanks!!

Re: kernel parameter

Johnson Punniyalingam — Wed, 20 Jan 2010 09:18:07 GMT

What Are the Side Effects of Changing the Value
This tunable has no effect on system behavior unless an application attempts to execute instructions located on its stacks. The majority of HP-UX applications are not programmed to do this.

Re: kernel parameter

Johnson Punniyalingam — Wed, 20 Jan 2010 09:18:42 GMT

Please take look at the below link

http://www.docs.hp.com/en/B2355-60105/executable_stack.5.html