Ubuntu之To reduce unnecessary disk I/O due to swappiness

In Ubuntu, there is a configuration value called vm.swappiness. It will control the threshold of memory usage. When the threshold reached, system will start the swap mechanism to swap data from memory to disk. For example, if you set vm.swappiness=65 and your computer has 4GB memory, it means when your system remains 4GB*65%=2.6GB, it will start to swap even if you only use 1.4G memory. Thus, I suggest you to set vm.swappiness to lower value, for exmpale, vm.swappiness=10, to reduce unnecessary disk I/O.

How to?
In terminal
1.# gksudo gedit /etc/sysctl.con
2.Add vm.swappiness=10 to the end of the file
3. Reboot computer

参考https://help.ubuntu.com/community/SwapFaq