Re: swapping?

How do you notice that if a system started swapping or not?

Thanks

On Thu, 2002-11-14 at 09:37, Shridhar Daithankar wrote:
> On 14 Nov 2002 at 10:30, Wei Weng wrote:
>
> > The term had been mentioned often enough on this mailing list. Can
> > someone enlighten me with some description or a URL where I can read on?
> > And why is it important to postgresql database performace?
>
> When programs request more memory than available, OS 'swaps' some memory to
> special area on disk and make the memory available. To programs, it gives
> appearance that nearly infinite memory is available.
>
> Unfortunately disk are hell slower than RAM and hence swapping slows things
> down as it takes much to swap in to disk and swap out of disk. Since OS does
> not care which programs get swapped, it is possible that postgresql instance
> can get swapped. That slows down effective memory access to knees..
>
> That's why for good performance, a serve should never swap..
>
> Bye
>  Shridhar
>
> --
> Peterson's Admonition:    When you think you're going down for the third time --
> just remember that you may have counted wrong.
>
>
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--
Wei Weng
Network Software Engineer
KenCast Inc.