Configurable Kernel Parameters

[Ricky_2]

Hi, why is it that the list of tunable parameters in /stand/system different from the list of configurable parameters in sam? So are all those parameters listed in sam changeable? How do I change them using the command line? Thanks.

[Stephanie Nicholls · Accepted solution]

Hi Ricky

Everything in /stand/system is something that has been changed eg: doesnt use the default parameter.

Everything listed as a configurable parameter in SAM is essentially changable but you should have a reasonable idea of what you are changing before you do so.

Check out the following link for more info on what each parameter is:
http://docs.hp.com/hpux/onlinedocs/939/KCParms/KCparams.OverviewAll.html

Personally I would go for changing parameters in SAM if you've never done it before as there are a number of interdependencies between parameters which SAM will alert you to and command line will not.

HTH

Steph

[S.K. Chan]

What you see in SAM are tuneable/changeable. What you see in /stand/system (right at the bottom of the list) are parameters that were changed before (so they are not complete list) Some other ways of listing your kernel parameters ..
# /usr/sbin/sysdef -n /stand/vmunix
or
# kmtune -S /stand/system | more

To manually tune kernel parameter ..
(for 10.x)
# cd /stand/build
# /usr/lbin/sysadm/system_prep -s system
# vi system
This is where you enter your parameter with its new value.
# /usr/sbin/mk_kernel -s ./system
# mv /stand/system /stand/system.prev
# mv /stand/vmunix /stand/vmunix.prev
# mv /stand/build/system /stand/system
# mv /stand/build/vmunix_test /stand/vmunix
# shutdown -ry 0

(for 11.x)
# cd /stand/build
# /usr/lbin/sysadm/system_prep -s system
# kmtune -S /stand/build/system -s =
The rest of the steps are similar (from the "mk_kernel" step onwards like above).

And yes .. be very sure you know what you're doing before you shy away from SAM.

[T G Manikandan]

The sam parameter listing are same to the system file.

Ofsource some changes cannot be done using SAM as it has a lot of dependicies like
YOu cannot modify ncallout This is because hp has a default setup which is good for the system results and which should not be modified unless the unix administrator is familiar with the kernel parameters.

If you are sure as what values should be assigned to the kernel parameters which should give you good performance you can use the manual way of assigning values to the parameters and doing a rebuild.

Also check this hp doc

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000058668851