As I stated the article I was asked to write was on MS Windows O/S and has not the slightest thing to do with Linux and I expressed my joy of not having to deal with it any more. Scott
M Harris wrote: > On Wednesday 09 May 2007 14:20, Registration Account wrote: > >> Personally IF the PC has the max amount of physical RAM installed AND >> still requires a Disk I/O to simulate more RAM then we really need to >> think about the fundamental operation of the O/S. How much RAM can it >> directly address and how much RAM does it need to juggle in and then >> does it requires a page file as well - Personally then its time to >> re-write the O/S in its memory management and its directly addressable >> RAM to process and the amount of physical RAM used by the memory manager. >> > The above paragraph is an over simplification, and not entirely correct > in > general, and not correct at all in terms of Linux. There are legitimate uses > for a swap file... and many linux installations make use of several large > swap files on each machine! My current desk machine has a swap file of 1024M > and real ram of 512M. I will generally set my swap file to twice the size of > main store--- but there is no such fixed rule. Having said that--- most of > the time my machine *never* swaps. I've been watching my new system monitor > (thanks Randall) now most of the afternoon and my machine has not swapped... > not once. As I have used the machine (mostly mail, small compiles, web > research) I have noticed the kernel adjusting my cache and buffer sizes and > moving along quite happily. This in contrast to my old W2000 and NT machines > that would constantly *thrash* after moderate use... this means many page > faults and lots of wasteful disk I/O like you talk about in your article. The > windoze platform has lousy memory management and even worse file system > management. The Linux kernel has *none* of these problems. This is no > exaggeration--- memory management on Linux is comparable to memory management > on MVS/XA, VM, SysV, Sys38, AS400, name it... seriously. > > >> Page file addressing should be a last resort by the O/S. Adding to an >> overworked disk I/O will slow things down ultimately, however the >> application will never fall over and you will never see the old "out of >> memory" error response which is the only advantage of such an arrangement. >> > (see above) Paging is used by the Linux kernel on a needs basis-- > absolutely. > And, sometimes those needs are very real and quite legitimate. The more you > play around with the Linux kernel the more comfortable you will become of > course, but rest assured--- you're in good hands. Its easy to create stress > scenarios for your machine that will tax memory and force paging... check it > out. > > > >
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