Things I Needed To Know

[chebe]

Problem: Linux uses up your 'extra' RAM for cache. But often refuses to free it when it's needed.

Solution: sync; echo 3 > /proc/sys/vm/drop_caches

Props: http://www.scottklarr.com/topic/134/linux-how-to-clear-the-cache-from-memory/

*edit*
http://www.linuxatemyram.com/
http://www.linuxatemyram.com/play.html
https://help.ubuntu.com/community/SwapFaq (to set swappiness)