Linux swappiness

Linux swappiness is the rate at which a Linux platform's kernel moves pages into and out of active memory.

The Linux platform does not wait until all available memory is used before swapping pages to disk. Instead, it swaps pages based on how long they have been inactive. Increasing the swappiness value makes the Linux kernel move inactive memory pages to swap sooner than when the swappiness parameter is low. 

Swappiness is defined by a tunable value called the swappiness parameter, which can be set on a scale of 0 to 100. Linux servers are typically set to a swappiness value of 60. Administrators will adjust Linux swappiness to account for high memory loads on a server or other factors related to workloads and available resources.