The first in a series of technical 'question and answer' guest posts written by one of the UKFast Linux aficionados I've seen a lot of people posting subjective explanations of what this does. Here is hopefully a more full answer. In the split LRU on post 2.6.28 Linux, swappiness is a multiplier used to arbitrarily modify the fraction that is calculated determining the pressure built up in both LRUs. So, for example on a system with no free memory left, the value of the existing memory you have is measured based on of the rate of how much memory is…