M... wrote: ... > I know swap used to be 2x the memory, but does that > still hold with 256MB RAM installed ? as opposed to > years ago with 32MB or 64MB ?
That advice is as bogus now as it was then. The answer is, "use what YOU need". Most of the time, if your system starts swapping, you are hurting. The "Swap = 2x Physical" rule makes a little sense if you have a LOT of applications loaded, but only a few are actually active at any one time, AND waiting for a swapped-out app to get reloaded into RAM and an inactive app to be swapped out is acceptable. That's an unusual situation for many, probably even most, systems. The other application I have found for swap is where one app will suddenly start demanding astronomical amounts of RAM for a brief moment, and the nature of the task is where it doesn't matter if it takes two minutes or twenty minutes. Usually, however, if you are running any kind of server and you expect swap, you need more RAM, not to be quibbling about swap sizes. Core dumps are saved to swap, but then, they get unloaded to /var on boot, so IF you care about this (and most people probably should not), you have to size several things appropriately...swap slightly bigger than physical RAM, and enough free space on /var to have at least one core dump, probably multiple. Nick.
