[root@sankar-test ~]# cat /proc/sys/vm/swappiness
60 -- default value
swappiness can have a value of between 0 and 100
swappiness=0 tells the kernel to avoid swapping processes out of physical memory for as long as possible
swappiness=1 tells the kernel to Minimum swappiness without disabling it entirely
swappiness=100 tells the kernel to aggressively swap processes out of physical memory and move them to swap cache
swappiness=60 (default) the swap file will be used fairly often if the memory usage is around half of my RAM.