Re: what is sufficient free memory?
> Thanks for all the reponses. From most of the replies, can I gather that
> I'll have to observe my how much is being swapped to determine whether I
> should immediately "up" the RAM back to 128MB? (and pester the tight-wad
> suits who'll approve the requesition)
Run the command vmstat, and observe how much is paged in /out, what is the
scan rate? That indicates how hard the page stealer is looking for pages it
can free off. vmstat 10 is usually a goodish, number but if you can run it
a long time, longer sample times is useful.
If you still have the 128MB in the machine, you could force Linux to ignore
it, using a boot parameter.
With lilo, that would mean an append line with 'mem=64M' in it, or enter it
at the lilo boot prompt.
boot: linux mem=64M
That way you can actually trial your system out, at the cost of a reboot, to
see the affect.
With squid, you probably want to lower the mem cache down to about 1/4 of
physical RAM, if it's higher than the default. Depending on usage perhaps
less than 16MB would be a waste of RAM, your call!
If the suits don't blink, then perhaps you could investigate interleaving
swap over a number of disk partions, by using mkswap, and swap entries in
fstab all set with a priority=5, instead of the defaults which don't