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Disabling memory swaping on HPUX 11.31

 
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GPissutto
Frequent Advisor

Disabling memory swaping on HPUX 11.31


Hello everyone,
I can't find any information telling me how to disable the memory swaping on 11.31, in previous releases it was handled by parameter swapmem_on, which is not longer used by the OS, so I really apreciate any help concerning this issue, I need machine to work with the whole memory for applications.

Best regards,
Cristian.
7 REPLIES 7
Tim Nelson
Honored Contributor

Re: Disabling memory swaping on HPUX 11.31

First finding from http://docs.hp.com/en/5991-6469/5991-6469.pdf

The tunable swapmem_on has been obsoleted. Pseudo-swap will always be enabled, as
was the default for previous releases of HP-UX.



Bill Hassell
Honored Contributor

Re: Disabling memory swaping on HPUX 11.31

Memory swapping is part of any virtual memory system such as HP-UX. If by the term: disable you mean that you do not want swapping to take place at all, then reduce your swap space to less than RAM size. This will cause programs to crash if they do not handle memory limits correctly so you'll not have to worry about swapping. The pseudo_swap concept was a way to allocate RAM without having matching space in the swap area.

> I need machine to work with the whole memory for applications.

This sounds as if you are confused about pseudo_swap. The concept is simply bookeeping. Pseudo_swap is space in RAM for programs and data that do not have a space on the disk. The term is often referred to as memory-based swap but that is quite incorrect. Pseudo_swap simply removes the restriction that every program and data area in RAM must be reserved some place in swap.

All of your memory is available to all of your programs, but if you are running legacy 32bit programs, these programs have extreme limitations on the amount of memory they can use.


Bill Hassell, sysadmin
Steven E. Protter
Exalted Contributor

Re: Disabling memory swaping on HPUX 11.31

Shalom Cristian,

I don't think you want to disable it. Swap is necessary for normal OS operation. To avoid swapping you simply throw more memory at the system than it will ever use.

SEP
Steven E Protter
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GPissutto
Frequent Advisor

Re: Disabling memory swaping on HPUX 11.31


Hello,
First at all, thanks to all of you for quick resonses.
Well, I don't want to disable swaping at all, I just want to know if it is possible disabling the pseudo-swap, as it was possible in the previous hpux releases by setting the swapmem_on parameter to 0. I have been trying to do some research about it without success, so, I don't know if I can do this by setting some new parameters in 11.31 or I just cannot do it at all on 11.31.
Thanks very much again.
Don Morris_1
Honored Contributor
Solution

Re: Disabling memory swaping on HPUX 11.31

No, it isn't. The parameter is obsoleted as "man swapmem_on" tells you (and others here). There's no new parameter [it would have been mentioned in the man page], there's no hidden parameter, there's simply no way to turn it off now.

If there's some reason other than idle curiosity you think you wanted to disable it, please state it so your concerns can be addressed.
Venkatesh BL
Honored Contributor

Re: Disabling memory swaping on HPUX 11.31

I think the point has been made very clear. Pseudo swap is ON on 11.31 by default, and cannot be turned OFF. There is no reason why you need to worry about it being ON. The applications would only benefit from it.
GPissutto
Frequent Advisor

Re: Disabling memory swaping on HPUX 11.31


I really apreciate all of your valuable comments and help...thanks very much indeed.