Hi, Heimo: I am glad that you saw my 'tongue in cheek' humor. ;-)
Heimo Claasen wrote: > > Ok, ok, Chuck - sure "it depends" ;) > (and oops, hwo do I use a swap _file_ instead of the "prescribed" > partition ?) # create and enable a 16 Megabyte swap file dd if=/dev/zero of=/swap bs=1024 count=16384 mkswap /swap 16384 swapon /swap # # swapoff /swap > >From your list, I conclude that it depends on all those six-and-a-half > factors, even if I'm not soooo convinced what for instance, "distro > AND version" Some distributions automatically install large window managers Gnome|KDE and some small WMs, swafish|twm|fvwm2 and some console only. Knowing the distribution might enlighten us about how much virtual RAM it would need. > (on top of the kernel number), the BogoMIPS or even the If a 100 bogoMIPS system ran two applications via 'at' or 'crond'; one at the hour and one at the half hour and each took 59 minutes to run and each consumed 51% of available memory, then swap would be needed. If the bogoMIPS were doubled, each would finish 30 seconds before the other started and no swap would be needed. > HD speed, would have to do with it. Uh, never mind about the HD speed. :-| > And then I have this experience with one (notabene experimental) sound > application which just doesn't care for how much swap there is - but > it is a darn memhog in itself: it crashes if the data file (or too many > together) loaded need too much _RAM_, regardless of how large I dimension > the swap. > So this real and practical example would tell me: no swap partition > needed (EXACTLY for this one app.) > > Another real-life case is with that not-so-brandnew laptop and its > "small" HD of 2 GB and "poor" RAM (48 MB) installed, where Linux has > to share space with a windoze and a small DOS partition. This runs > vanilla apps in Linux - a GUI + a browser (including the connectivity > gears) + a plug-in pic viewer at most, simultaneously. Here, seen HD > space and RAM available (both hugely enormous, seen from my past-&-present > DOS uses; all real work, including almost all net-work needed, is done > in text mode and in the miniscule DOS compartment), the volume to set > aside for a swap partition is even a "critical" decision. If you mount the DOS partitions, you could create swap files on their unused HD space. > Then there is one factor which you did not mention but which might be > of decisive importance: if a unit is used by one person, it would most > probably have just one user (and a very few "user accounts" only) and > simultaneous use of different apps would be probably limited or rather, > the user-"system-owner-administrator" could be enabled to establish a > reasonable estimate of the real need for swap space on the perhaps > not-so-enormously-new/big-HD -- _if_ s/he had some ways or indications > for calculating it. > > I think this is a reasonable demand, and I'm looking for some means to > answer to this. So, how would I measure how much swap this kernel or > that application (in combination with what GUI, for instance) would > need, in fact ? I have been wondering this also. I often run 'top' and watch the top several lines of the 'top' display. I need to understand more about what each value means. Actually, 'free' displays the same information. 'top' is fancier to watch. ;-) If I knew how to 'flush' all swap space, I could 'flush', run some applications, then see how much swap was used. > > it may be suggested EXACTLY how much swap space you will need. > > Hmm, for that laptop for instance, running yet a much too FAT Mandrake 8.2 > with kernel 2.4.18 (because Debian would not find the good video driver > for the trickish LCD). I would gladly dish the mem-(and how much swap-?) > hogging KDE and Nutsrape with it; though, regrettably, it must be able to > run X and a SSL-capable net connection. I can run Netscape under fvwm95 and XFree86 v4.2.1 on my laptop with 16 Megabytes of RAM, 32 Megabytes of swap, Slackware v8.0, kernel 2.2.19. So that much will squeeze into 48 Megabytes of virtual RAM. Perhaps XFree86 v4.2.0, 4.1.x, or 3.3.x would consume less memory. :-| HTH, Chuck > > I understood James' earlier questions quite similar to what I would ask > for this example; and feel the are still not answered: > > "if said user had less than X MB RAM, they will definitely need a swap > > partition"? And what about guidelines for swap partition size in such a > > case: can such be stated as well? Like, say, "if this individual has > > only 32 MB RAM, he should have a 64 MB swap partition" or "if he has 64 > > MB RAM he'll only need a 64 MB swap partition"? > > <besides>IMNSO too many of the posts especially on this list here - > where I suppose are precisely quite a lot of "single-users" listening, > and quite some who did or want to change away from Winno$ with their > existing, "old" PCs - are geared towards conditions of illimited means > (e.g., permanent/broadband net connection, units with huge mem and dito > HDs); which might well be a misconception.</besides> > > // Heimo Claasen // <hammer at revobild dot net> // Brussels 2002-12-14 > The WebPlace of ReRead - and much to read ==> http://www.revobild.net - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs
