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Re: [K12OSN] Quick Question about Swap partitions



Jim Kronebusch wrote:
It depends on the use pattern, but on machines I've seen as you get close to 2 gigs into swap the machine will be so slow and unresponsive that you'll probably reboot it before it would recover - if it ever does. The main point is that you need enough RAM. Swap will keep the machine from crashing if you run short momentarily but its not a real substitute.

So then theoretically is there a problem with having too much swap available?  I want to
be sure I have enough in a just in case scenario, but if too much will also slow things
down I want to keep it to a minimum.

No, it just won't be used unless you need it.

For example let's say you have a system with 16GB RAM and a 2GB swap, would this perform
any differently than a machine with 16GB RAM and 10GB swap?  If both perform the same,
and you have enough space, wouldn't the setup with more swap be safer if a sudden high
use case came about?

Yes if the high use case comes at night when nobody cares... When users are active they aren't going to like it when they have to wait for several gigs of disk reads and writes between their keystrokes.

Obviously if events kept repeatedly using all the RAM and digging
deep into swap usage, you would add more RAM for the future and hope to stay out of swap
completely.

There's the famous quote from supercomputer designer Seymour Cray in the late 70's:
"Memory is like an orgasm. It's a lot better if you don't have to fake it"
I don't think it has changed much since.

--
  Les Mikesell
   les futuresource com



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