How manu swap ?

Albert Shih Albert.Shih at obspm.fr
Wed Jan 16 08:37:17 PST 2008


 Le 16/01/2008 à 10:28:06-0600, Dan Nelson a écrit
> In the last episode (Jan 16), Albert Shih said:
> > Hi all
> > 
> > I known it's classic question. 
> > 
> > Long time ago when I install a FreeBSD x86 32 bits when I have N Go
> > of Ram the installer take 2xN Go for the swap partition.
> > 
> > Now I just install two machine with FreeBSD amd64 version with 8Go of
> > Ram and FreeBSD installer take 4 Go of swap.
> > 
> > Is a bug in the installer or now FreeBSD don't need 2xRam of swap ?
> 
> When was the last time you saw your swap partition with more than 2GB
> in use?  On an 8GB system, you probably will either never have enough
> processes to require swapping at all, or you will have one or two
> processes so big that if they ever swap, it's a sign you need more RAM,
> not more swap :)  In systems with that much RAM, swap is pretty much
> only used for crashdumps, and with minidumps enabled by default, you

OK. I never need this because FreeBSD never crash....well more specific : I
never see FreeBSD crash and event it's crash I not qualify to use
crashdumps ;-)

> don't need much.  On small systems, the 2x-swap rule was because once
> you allocated enough processes to require that much swap, you were
> pretty much thrashing your system anyway.

OK. 

Thanks for your answer.

Regards.

--
Albert SHIH
Observatoire de Paris Meudon
SIO batiment 15
Heure local/Local time:
Mer 16 jan 2008 17:35:44 CET


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