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Re: Peoplesoft swap size recomendation?

 
Dan Copeland_1
Advisor

Peoplesoft swap size recomendation?

Can anyone tell me where I could find the swap size recommendation for Peoplesoft (if they give one)? Having a time finding it elsewhere online.

Thanks
2 REPLIES 2
Ravi_8
Honored Contributor

Re: Peoplesoft swap size recomendation?

Hi,
the swap size assignement is not depending upon the application, it depends on RAM size(usually twice of RAM), all softwares recommends RAM size not the swap size
never give up
Pedro Sousa
Honored Contributor

Re: Peoplesoft swap size recomendation?


from doc: http://www.docs.hp.com/cgi-bin/otsearch/getfile?id=/hpux/onlinedocs/os/11.0/tuningwp.html&searchterms=swap%20size&queryid=20010705-071157

"How Much Swap Do I need?

The amount of swap, added to the amount of memory available, defines the virtual memory available for processes. The minimum recommendation is twice as much swap space as physical memory. Keep in mind, this is an "old" formula. If you have two, three, four or many more gigabytes of physical memory, this would result in way too much swap space. Granted, there are the pathological cases that would require you to have eight to ten gigabytes of swap with, say, four gigabytes of physical memory. If you try to execute a process that would exceed the amount of available memory plus available swap, you will get a "out of memory" message. If you configure more swap than you will ever need, you are wasting disk space. The correct swap size will vary considerably depending on the size and number of application(s) run on a system.

The correct swap size can be determined by monitoring swap usage while working with real data. This could be done either with the swapinfo command or using a tool like HP's GlancePlus. GlancePlus allows you to monitor system resources on a per process basis and will display the high water mark (since you started glance). You would configure a system with more swap space than you expect to need, then run GlancePlus while running an application(s). By monitoring the high water mark, you can determine the maximum swap space used and adjust the swap size accordingly. Obviously, if you experience out of memory errors, swap size is too small.

There are many systems with less swap space than physical memory. This is perfectly fine. The person who specified the system probably recommended all that memory so that they would not have to swap! We have seen systems with with swap space equal to 50% that of physical memory. Just be sure to have swapmem_on EQUAL TO 1!!

NOTE: For best performance, swap space should be distributed evenly across all disks configured with swap, at the same priority "

good luck.