Kernel (VM) swap problem in Hoary

Paul M. Bucalo ubuntuser at
Tue May 31 18:49:31 UTC 2005

I've had this same problem in FC 3 and couldn't (well, really wasn't
smart enough) to resolve it: kernel wastes up to 98% of available RAM to
cache and hold dirty pages too long while memory is desperately needed
for applications. Then, extensive swap-thrashing that leaves the system
nearly useless for up to 30 minutes. It seems to be more an issue on the
desktop with 2.6 kernels.

There are numerous configuration files in /proc/sys/vm that control this
issue. I've just not found the magic numbers that should work best for
my system. I'm running with 256 MB RAM and an AMD K6-2/500 MHz
processor. (Btw, 'readahead' is active.) 

My research hasn't turned up much over the past few months. If anything,
I get the impression this is still an area of more mysticism than
science. Anyone worked over these files and have some suggested numbers
I should test out? Any recommendations, pointers to URL's,
what-have-you, greatly appreciated. I have two family members I wish to
convert to Linux and this is all that is holding me up from doing so
with Ubuntu (or any other distro using a 2.6 kernel).



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