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Re: swap_memory

 
Indrajit_1
Valued Contributor

swap_memory

Hi all;

What is the maximum "maxswapchunks" i can increase in kernel parameter on 9000/800/rp8420. The Physical mem is 45gb. My current swap memory is 46gb. i need to increase to 88gb.Please help me.

Cheers
Indrajit
Never Ever Give Up
7 REPLIES 7
Luk Vandenbussche
Honored Contributor

Re: swap_memory

Hi,

The maximum kernel parameter for maxswapchunks is 16384.

See also

http://www5.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000080025377
James R. Ferguson
Acclaimed Contributor

Re: swap_memory

Hi:

The 'maxswapchunks' maximum value is 16384 chunks. A chunk is a 1KB block of swap. Hence, you may also need to raise 'swchunk' to be able to define a very large swap space. See:

http://docs.hp.com/en/TKP-90202/index.html

Regards!

...JRF...
Steven E. Protter
Exalted Contributor

Re: swap_memory

Shalom Indrajit,

Note that the normal rules for swap setup do not apply to a system with so much memory. You may do fine with swap set to half of physical memory or equal to physical memory.

Setting it to 88 GB on a system that never pages or even reserves a fraction of that is a waste of disk space.

SEP
Steven E Protter
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DCE
Honored Contributor

Re: swap_memory



Make sure you have the kernel parameter

swapmem_on=1

This allows you to use psuedoswap.

Indrajit_1
Valued Contributor

Re: swap_memory

Hi All;

Yes, the output of the command sysdef shows that the max size can be 16384. But is there any dependency for increasing the maxswapchunks ?

Cheers
Indrajit
Never Ever Give Up
Don Morris_1
Honored Contributor

Re: swap_memory

The only dependency for increasing maxswapchunks is that you have sufficient memory for the kernel to allocate the resulting structures (these aren't that big, so in general if you need to increase it -- do so, you aren't going to miss a few kb of memory).

As others have mentioned, in your case you'll have to increase swchunk as well (since the default swchunk value plus the maximum of maxswapchunks only gets you to 32Gb of swap).
Indrajit_1
Valued Contributor

Re: swap_memory

Hi All;

Thanks a lot for ur suggestion.I need to modify the kernel parameter. Hope it will work fine.


Cheers
Indrajit
Never Ever Give Up