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Re: OT (slightly) swap limits

On Thu, Apr 24, 2008 at 05:00:51PM -0400, Patrick Ouellette wrote:
> On Thu, Apr 24, 2008 at 04:45:05PM -0400, Damon L. Chesser wrote:
> > 
> > Being in an interview loop looking for employment, I find I am asked  
> > questions I never considered, for example:  How much is enough swap?
> >
> Rephrase the question.  Ask what the intended use of the machine is,
> what response times the users expect, how much real RAM is there, and
> what applications/services will run off the machine.
> Then tell the interviewer how each parameter you've asked about would
> influence your decision on how much swap was enough.
> How much is enough?  As much as the system needs to run and not kill 
> processes due to lack of memory (real + swap).
> I've run machines with 1Gig or more RAM with NO SWAP.  I've also run
> machines with 4Gig of RAM and 16Gig of swap (BIG datasets).

IIRC, historically, the 2X ram thing comes from UNIX where in the event
of a crash, a crash-dump of memory goes into the swap partition, also
UNIX does/did heavy paging out of pieces of idle software to free up memory
for use by running progams, much more agressively than Linux.


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