Kernel Parameter Change

[Debbie Downing_2]

Can someone advise me why when I change the value of maxuprc from 1500 to 3687 on HP 11i after each reboot of the machine the value defaults back to 1500 again, this is a dynamic setting so I cannot understand why it is defaulting back when the machine is being rebooted.

Any ideas would be greatly appreciated.

Regards


Debbie

[Pedro Cirne]

Hi,

I think you must compile a new kernel if you want to make changes permanent after reboot.

Regards

[John Palmer]

Hi Debbie,

What have you got nproc set to? maxuprc must be less than nproc.

Regards,
John

[Ivajlo Yanakiev]

HI,

If you want ot keep new value of maxuprc permanently. You must rebuild you kernel.

1. Start sam/kernel or kcweb
2. change maxuprc
3. rebuild kernel
4. reboot server


Or you cant set maxuprc every time when you start your server using some start script.
But I do not recommend.

[Debbie Downing_2]

John

I have nproc set to 4096, so maxuprc is set lower than this.

Thanks

Debbie

[Ivajlo Yanakiev]

It can be usefull
http://www.interex.org/pubcontent/enterprise/mar01/10sysad.html

[Eric Antunes]

Hi Debbie,

To make the changes effectives you must put them in /stand/system file (see kmtune).

Best Regards,

Eric Antunes

[Debbie Downing_2]

The new value is present in /stand/system when I do a grep maxuprc it shows me the new value 3687, so isn't that a permanent change if it is contained here???

Regards

Debbie

[Ivajlo Yanakiev]

Yes system file contain all value and parameter that you next kernel will have.
Rebuild your kernel

[Eric Antunes]

Hi,

The easiest way to do this is using SAM:

#sam (Kernel Configuration -> Configurable Parameters -> (Select parameter to change) -> Action -> Modify Configurable Parameter... (Here you can use a static value or a formula)-> (Do this to all parameters you want to change and, after that Process New Kernel) -> Process New Kernel

Hope this'll help

Eric

[Debbie Downing_2]

Eric

This is where I set the parameter in the first place, so not sure why it isn't staying permanent.

I'm confused with what is happening.

Thanks for your help

Debbie

[Eric Antunes]

Debbie,

Why do you want a this big value? I have this parameter setted to (NPROC*9/10) because you just can't have more user processes (maxuprc) that the maximum number of processes (nproc)

So, I tried to set it to 3687 but, I got the error:

Error: One or more tunable parameters violates an interdependency rule. SAM expects the following expression(s) to be true:

maxuprc < (nproc-4)
maxuprc <= (nproc-4)

[Debbie Downing_2]

Eric

Oracle DBA is trying to install oracle10 and it issues a report in the event of any failures as to why it cannot install the software, it failed installation because of missing patches... which have now been installed and also that the maxuprc value needed to be set to 3687. This was changed and I made sure nproc was set to a higher value.

Regards


Debbie

[Ivajlo Yanakiev]

Yes maxuprc is dynamic parameter and you can set value for it, and you done this.
Your problem is that default value for maxuprc is config/set in yopur kernel with diferent value. When you reboot your server, you read your kernel and load old value for maxuprc. If you want to change default value for maxuprc you must rebuild kernel with new value for maxuprc.


P.S. kmtune change value until next reboot.

[Ivajlo Yanakiev]

/stand/vmunix is your kernel.
/stand/system is text file contain value of param and drivers which will be use for build new kernel.

Your curent kernel do not read or write in this file and will work without it.

[Debbie Downing_2]

I'll rebuild the kernel and then see what happens. Thanks for all your help

Regards

Debbie

[Eric Antunes]

With SAM yo ucan see if other parameters are affected. That's why I always use SAM. But you can do it on the command line:

#cp /stand/system /stand/system.bak
#vi /stand/system (do the changes you want and save)
#config /stand/system (after this check if it created vmunix_test in your local directory)
#cp /stand/vmunix /stand/vmunix.bak
#mv /stand/vmunix_test /stand/vmunix
#shutdown -r -y

Best Regards,

Eric

[Eric Antunes]

It is better to move to /stand first so that vmunix_test file is created in /stand directory...

[Debbie Downing_2]

Eric

Thank you so much for your help, I will schedule to do this and see what happens, thanks again.

Regards

Debbie

[Eric Antunes]

You welcome Debbie! Be always careful when tuning the kernel and be sure you have a backup.

One more thing, I've just noticed that you have assigned points to just 6 of 87 responses. The more you assign points to responses, the more (and the faster) you will get replies (sorry if the English isn't good :( )...

Eric