In reply to Lars Wirzenius's message: > A R Abid: > > I have got 16MB of RAM on my machine. Could someone tell me if it would > > still be necessary for me to create a Linux swap partition. > > The terse form of the formula is: > > swap needed = total memory need - physical memory size > > (Forget everything about "twice physical size". That is an evil > prank that people play on the uneducated rich who have bouth > 512 MB of RAM.)
Thank you for finally getting that right! Actually the 'twice physical memory' formula is about right for some Unix systems, HP-UX in particular. HP-UX pre-allocates swap space for physical memory, and then pre-allocates swap space for every job when it starts or malloc memory. Your formula is definitely the right one for Linux, though. > First you need to estimate your total memory need. This depends > very heavily on what you do and what programs you run at the > same time. I need about 30-40 MB to run a mailer, Mosaic, > xpat2, up to a dozen or so xterms and editors, a HTTP server, > a news server, a mail server, compilers, makes, the X server, > window manager, a clock, xload, desktop pager, window list, > and a few other niceties. Gcc also needs several megabytes for compiling, and I recently discovered the Java compiler needs 8-10 megabytes to compile a program. On the other hand, if you are only using virtual consoles with simple programs, then 8 MB total *might* be enough. If the original person is going to be running X11, then he probably wants to add at least 8-16 MB of swap. > For a somewhat more detailed explanation, read the memory > management chapter in the System Administrators' Guide. The > current version is 0.3, but 0.4 is imminent (I need to see > how it looks on paper, but if there aren't any big problems > with the that, I will release it in a couple of days). Thanks, glad to hear that.
