topic Increase the tunable parameter maxswapchunks in Operating System - HP-UX

Increase the tunable parameter maxswapchunks

Manuales — Sun, 09 Sep 2007 04:25:43 GMT

Hi, when i started a server, i run dmesg command and i got the following .. what do i have to do? i mean, i do not understand what system means, could you pleas explain me?

thanks in advance ...

Unable to add all swap for device: /dev/vg01/swap3. Increase the tunable parameter maxswapchunks by 1256 and re-configure your system.

Regards.

Re: Increase the tunable parameter maxswapchunks

Steven E. Protter — Sun, 09 Sep 2007 04:27:49 GMT

Shalom,

It would seem you have extended swap beyond the capacity with the current maxswapchunks setting.

Quick fix is to use sam to set the parameter higher. You will then need to reboot the system to make the change to swap active.

SEP

Re: Increase the tunable parameter maxswapchunks

Manuales — Sun, 09 Sep 2007 04:56:08 GMT

this is the value:
Formula Value: 3500
Calculated Value: 3500

what is the relation betbween log says:
"...Increase the tunable parameter maxswapchunks by 1256..." and the value that actually it has (3500) ?

what valor do you suggest?

how do i know if i can change it online without shut down the server?

Please let me know.

Re: Increase the tunable parameter maxswapchunks

Manuales — Sun, 09 Sep 2007 05:18:33 GMT

help please !!!! :)

Re: Increase the tunable parameter maxswapchunks

Steven E. Protter — Sun, 09 Sep 2007 06:21:32 GMT

I suggest you increase the current figure 3500 to at least 5000.

I also suggest you not use forumulas to calcuate this value. Use sam to override the forumula and plug in your needed value.

SEP

Re: Increase the tunable parameter maxswapchunks

James R. Ferguson — Sun, 09 Sep 2007 08:19:18 GMT

Hi Manuales:

This is straighforward. Choose a value for 'maxswapchunks' that is at least 1256 larger than your current value.

I prefer an integer number of 256 increments up to a maximum value of 16,384.

You can consult the 11.0 kernel tuning document for an understanding of this parameter. It applies well enough to 10.20 in this case:

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

Regards!

...JRF...