How much swap?

[Giles Orr]

There's this old story that swap space should be equal to twice your
RAM, and I've heard it for more than a decade of working with Unix.
But I've never seen a satisfactory explanation (or any explanation at
all) of why this should be so.  I have this bizarre idea that the more
RAM you have the less swap you need, and that a person with 4Gb of RAM
*doesn't* need 8Gb of swap.

Obviously this will be dependent on application: a person who expects
to be manipulating multi-layer 24"x36" images in the GIMP might
consider 12Gb of virtual memory merely adequate, and servers will have
other considerations.

Can anyone explain the whole swap=2xRAM thing to me?  Thanks.

-- 
Giles
http://www.gilesorr.com/
gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org
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