One of my servers is crashing once in a few days.
It does web serving + some background jobs like XML file processing.
If you look at the screenshot http://awesomescreenshot.com/075xmd24 you'll see that the server swaps although it has lots of free memory. Why does this happen? Why doesn't the OS use the free mem instead of swapping ?
The web serving is low traffic (maybe it has high load when google crawls it)
Server details: Ubuntu 11.10 oneiric i386 scalarizr (0.7.185) python 2.7.2, chef 0.10.8, mysql 5.1.58, apache 2.2.20, php 5.3.6, memcached 1.4.7 Amazon EC2 (us-west-1)