topic Re: maximum swap for HP-UX 11.11 in Operating System - HP-UX

maximum swap for HP-UX 11.11

Marvin Diaz_1 — Wed, 06 Jul 2005 21:10:55 GMT

Hi Guys,

I got a server rp8420 with a memory capacity of 64GB. I want to create a swap of 64Gb however it limits me to 32GB. I there any way to make my swap single into 64GB?

marv's

Re: maximum swap for HP-UX 11.11

Devender Khatana — Wed, 06 Jul 2005 21:20:54 GMT

Hi,

What is the error it gives while configuring single swap device as 64GB ? Actually what is the size of your disk were you are creating this ? It is always recomended two have huge swap distributed across multiple disks for better performance.

HTH,
Devender

Re: maximum swap for HP-UX 11.11

Marvin Diaz_1 — Wed, 06 Jul 2005 21:24:50 GMT

Hi Devender,

During the installatin of OS, upon input of 64GB swap, it automatically change to 32gb

Re: maximum swap for HP-UX 11.11

Devesh Pant_1 — Wed, 06 Jul 2005 21:26:41 GMT

Marvin,

Kernel limits the amount of swap space by a multiple of two parameters
maxswapchunks and swchunk
Swapspace = maxswapchunks * swchunk

If you increase the maxswapchunks to the max , rebuild the kernel and reboot, you will be able to push the swapsize.

Do you have pseudo-swap enabled? It is controlled with the kernel parameter swapmem_on.
It is highly unlikely that you will require such high swap size. As a result I would advise you to use pseudo swap. Pseudo-swap is equal to 7/8 of available memory at system startup.
thanks
DP

Re: maximum swap for HP-UX 11.11

Devender Khatana — Wed, 06 Jul 2005 21:29:49 GMT

Hi Marvin,

It is the swap chunk size who default value with a max. value of swap chunks support only 32GB. You need to extend swap chunk size.
Have a look at the thread.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=622300

HTH,
Devender