On Tue, Apr 03, 2007 at 11:20:41PM +0800, John Summerfield wrote: > Bart Schaefer wrote: > >On 4/3/07, Pham Hai <haisoncompany at gmail.com> wrote: > >>To install Oracle Database 10g, I need to increase the swap memory to > >>1004 > >>MB. > > > >Tangential aside: Does anyone have an informed opinion on whether the > >"swap should be double RAM" rule still makes sense? > > It never did. I couldn't see why, if I upgraded my Pentium from 64 It used to make sense on older BSD systems (eg SunOS 4) because of how the virtual memory paging system worked. If you had 'n' Mb of RAM then the first 'n' Mb of swap was used to "shadow" RAM somehow (I'm hazy on the details) and so if you had '2n' of swap then you only had '2n' of virtual memory, not the '3n' you'd expect. Linux never did this and I believe newer BSDs don't either. The "swap=2*RAM" never made sense for Linux. > Mbytes+128 Mbytes I should add swap if I added 128 Mbytes RAM. Under the older BSDs adding memory without increasing swap didn't result in larger VM sizes because of the above description. Fun, huh? :-) -- rgds Stephen