how to set the kernel parameters in hpux

[senthil_kumar_1]

Hi

I am using hpux 11.00 and 11.11.

I knew "how to set the kernel parameters in linux".

The file "/etc/sysctl.conf" is used to set the kernel parameters in linux.

Like this how to set the kerner parameters in hpux 11.00 and 11.11.

1) what is the file is used to set the kernel parameters?
2) how to view all current kernel parameter settings?
3) How to set the new kernel parameter with out restarting the server?

[George_Dodds]

Do a man on kmtune.

Cheers

George

[avizen9]

Hello Senthil,
please refer below good doc,

http://docs.hp.com/en/939/KCParms/KCparams.OverviewAll.html

[Suraj K Sankari]

Hi,

You can change kernel parameter through SAM.
from command line also you can change the parameter.

"Overview of Kernel Configuration Parameters"
See the below link your all answers are there.

http://docs.hp.com/en/B8725-90143/ch13s03.html

or Download the pdf file

http://docs.hp.com/en/B8725-90143/B8725-90143.pdf

See the attache file how to change kernel parameter through command line.

Suraj

[Pete Randall]

Actually this is one of the cases where I prefer to use SAM. The SAM interface has valuable help sections which can explain some of the more obscure kernel parameters and their relationships to other parameters - potentially valuable help in my opinion.


Pete

[Sunny123_1]

Hi Senthil

Best way to use SAM

go to sam > Kernel Configuration > Configurable Parameters.

Or use kmtune.

Regards
Sunny

[Sajjad Sahir]

Dear Senthil

Please check the following link, it is an excellent one

http://docs.hp.com/en/1219/tuningwp.html

thanks and regards

Sajjad Sahir

[johnsonpk]

Hi Senthil,
>>1) what is the file is used to set the kernel parameters?
/stand/system is used to create /set kernal tunables.(changing the system file entries doesnt mean that you have set the kernal tunables on the kernel)
>>2) how to view all current kernel parameter settings?
#kmtune (till 11iv2)
#kctune (v2
and v3)
>>>3) How to set the new kernel parameter with out restarting the server?
Reboot is required for tunables that are static
You can use SAM or change it as belo
(if you are tuning the dynamic parameters using kmtune -s = it will have immediate effect(not reboor required))
1)Modify the system file either by vi or by command
# kmtune â s dbc_max_pct=35

2)Generate the kernel
after you modified the system file as needed you can generate the new kernel using the
mk_kernel script. The name of the new kernel will be /stand/build/vmunix_test
unless explicitely specified through the -o option. The -s option specifies the system
file to use, /stand/system is the default:
# mk_kernel

3)Schedule kernel update
kmupdate is used to initiate the move of the new kernel (/stand/build/vmunix_test)
and the corresponding files to their appropriate places at the next shutdown or startup.
The current kernel will be copied to /stand/vmunix.prev
# kmupdate

4)the new kernel will be activated by restarting the system:
# cd /
# shutdown â r 0


Rgds
Johnson

[Rahul Rai_1]

Hello Senthil,

Before changing Kernel Parameter be sure there is two type of Kernel Parameter

1) static, where reebot require, to make effective.
2) Dynamic where no need to reebot.

well, sam is the best way to change the kernel parameter, there is some dependencys with other kernel parameters, and it will simply display the formula.

sam > Kernel Configuration > Configurable Parameters

Regards,
Rahul Rai.

[Don Morris_1]

Note that 11.0 had no Dynamic tunables, only Static. (11.11 introduced Dynamic tunables).

[UVK]

Depending on OS version it varies.

If you dont wanna take risk use SAM easy and best way.

kmtune can be used from command line. read man pages for different switches.

-UVK

[Kranti Mahmud]

Hi Senthil,

Check the below link:

http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ibm.db2.udb.uprun.doc/doc/t0008238.htm

http://www.linux.org/docs/ldp/howto/Oracle-9i-Fedora-3-Install-HOWTO/sect_05.html

http://www.cyberciti.biz/howto/question/static/linux-kernel-parameters.php

Rgds-Kranti

[Md. Minhaz Khan · Accepted solution]

Dear Senthil,

As your OS version is 11.00 and 11.11

I can give you an example how to modify kernel in HP-UX without using SAM(SAM is recommanded):

Say you want to modify "maxvgs" parameter

1.
#kmtune -q maxvgs

OR
#kmtune|grep -i maxvgs

2.
#/usr/lbin/sysadm/system_prep -s system

#cd /stand/build

#ll system

................system----->Newly created

3.
#vi system


maxvgs 15----->Add this line at the

:wq!

4.

#mk_kernel -s ./system

5.

#mv /stand/system /stand/system.old

6.

#cp /stand/build/system /stand/

7.

#kmupdate /stand/build/vmunix_test

8.

#shutdown -ry 0


Note:

If new kernel was not able to boot follows the below procedure:

Step 1: Booting from the Backup Kernel:
To boot the backup kernel, /stand/vmunix.prev, boot the system manually as described below:

[POWER] #Power-on the system.

[ESC] #Hit the escape key to interrupt the boot process.

Main Menu> boot pri #Boot from the primary boot disk.

Interact with the IPL? Y #Do interact with the IPL/ISL.

ISL> hpux ll /stand #Shows the content of the boot filesystem /stand

ISL> hpux -is /stand/vmunix.prev #Boot from the original kernel and goto single user

Step 2: Moving the Original Kernel Back into Place
After booting the system, you may wish to make the original kernel the default so future reboots can proceed without any intervention from the administrator:

#mount /usr
# cd /stand #Move to the /stand directory.
# mv system.prev system #Move the original system file back into place.
# kmupdate /stand/vmunix.prev #Move the original kernel back into place.
# shutdown â ry 0 #Reboot the system with the original kernel.



**Note 1: If â cd â or â mvâ or â kmupdateâ command not work after booting the system into single user mode mount /usr directory.

#mount /usr

**Note2: To Shows the content of the boot filesystem /stand give the following command.This is useful if the kernel cannot be found.

ISL> hpux ll /stand


Thanks
Minhaz

[Aryan]

hi,

May be attached document will help you out about kernel's query..

Regards,
Aaryan

[senthil_kumar_1]

Hi All,

I am using HPUX 11.00 and 11.11.

How to find static and dynamic kernel parameters?

Can dynamic parameters only be set using "kmtune" and doesn't require restart?

Can static parameters only be set by system file and needs restart?

Pls explain me.

[Sivakumar MJ._1]

Check this ITRC forum

http://forums11.itrc.hp.com/service/forums/questionanswer.do?admit=109447626+1246286971604+28353475&threadId=1049933

[Duncan Edmonstone]

As the way you managed kernel parms from the command line was different in 11.00 to 11.11, you're probably better off just using SAM. That menod should be pretty consistent on both releases. SAM will tell you if a kernel parameter is static or dynamic (at least for 11.11, 11.00 is all static)

HTH

Duncan

I'm sure I've mentioned this to you before, but you do know 11.00 is out of support don't you??

HTH

Duncan

[Steven E. Protter]

Shalom,

kmtune, not kctune will show all current parameter settings in the Os you list.

kmtune -l

Check the man page for additional options to display which are dynamic.

11.00 has very few dynamic parameters, 11.11 a few more.

kmtune can set any dynamic parameters on the fly.

sam kernel configuration has some limited documentation on kernel parameters.

SEP

[Sunny123_1]

Hi

Dynamic kernal parameter not requierd reboot.But static kernel parameter requierd reboot.

Regards
Sunny

[senthil_kumar_1]

can we set value for static kernel tunable using kmtune?

[James R. Ferguson]

Hi:

> can we set value for static kernel tunable using kmtune?

Yes.

Regards!

...JRF...

[Suraj K Sankari]

Hi,

>>can we set value for static kernel tunable using kmtune?

Yes you can.

Suraj

[Ganesan R]

Hi Senthil,

Yes. you can. But the notable point is, by the name implies it needs kernel rebuilt to impact the changes.

[senthil_kumar_1]

Hi All,

I have understood something as follows.

1) We can modify the dynamic tunable by kmtune and doesn't require reboot.

2) We can modify the static and dynamic thru recompiling the kernel and make new entries in stand file. it requires reboot.

3) We can modify the static thru kmtune but needs to recompile the kernel and reboot the server.?

I know 1 and 2. But i dont know 3. how to implement 3.

[James R. Ferguson]

Hi:

> But i dont know 3. how to implement 3.

Use SAM or see here:

http://docs.hp.com/en/B2355-90950/ch03s10.html

Regards!

...JRF...