Re: Re: Apparently no swap configured

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Stephen Harris wrote:
" Swap should equal 2x physical RAM for up to 2 GB of physical RAM, and
then an additional 1x physical RAM for any amount above 2 GB, but never
less than 32 MB.

That's a silly recommendation, and never been true for Linux.  RedHat
don't always know what they're talking about.

I disagree with that. It has been true for linux for a long time, and is true even now. When was the last time you looked at the linux swap handling code ?

Recently, with large amounts of ram available on physical machines, eg > 2 GB, you need to start reconsidering a part of that strategy based around the fact that if your machine is really using 2 GB+ of swap, there might be other problems that need fixing and the absurd levels of latency introduced by that would mean those other issues really need looking at.

I'd still go with 2xRAM size for swap size upto a swap size of 2 GB, then make it the same as RAM size, till you get to 32 GB, at which point, half of real RAM size till 128 GB. Beyond that point, you really should be doing some benchmarks and monitoring to work out how much swap you need, and where it needs to be.

The other school of thought that seems to be doing the rounds is, 2xRAM till 4 GB, then just leave swap at 4GB irrespective of what your real machine RAM is, as long as its a multiple of 4.

--
Karanbir Singh : http://www.karan.org/  : 2522219@icq
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