There are several files in /proc/sys/vm you can use to tune the memory system with. You inspect them with 'cat', and set them with 'echo'. For example, /proc/sys/vm/freepages: '# cat /proc/sys/vm/freepages' may yield: 64 96 128 These three numbers are: min_free_pages, free_pages_low and free_pages_high. You can adjust these with a command such as: # echo "128 256 512" > /proc/sys/vm/freepages Free memory never goes down below min_free_pages except for atomic allocation. Background swapping is started if the number of free pages falls below free_pages_high, and intensive swapping is started below free_pages_low. A "page" is 4 kB. The values selected as boot defaults are the following: For a machine with n>=8 Megabytes of memory, set min_free_pages = n*2, free_pages_low = n*3 and free_pages_high = n*4. Machines with 8 Megabytes or less behave as if they had 8 Megabytes. If "out of memory" errors sometimes occur, or if your machine does lots of networking, increasing min_free_pages to 64 or more may be a good idea. free_pages_low should probably be about double of min_free_pages. After a period of inactivity, the difference between free_pages_high and free_pages low is immediately available for any program you want to start up, without any need to swap out anything else. If your memory is large enough (e.g. > 16 Meg), keeping 2 or 3 megabytes of memory ready for this purpose is probably a good idea. I've found that # echo "128 256 1024" > /proc/sys/vm/freepages gives good performance for a 32 Meg system used as a small server and personal workstation. The other three files in /proc/sys/vm are undocumented, as yet. Thomas Koenig, ig25@rz.uni-karlsruhe.de