With the ever increasing cost of the Hardware, the amount of physical RAM available on the system is increasing day by day. For example, couple of years back, I had a system which was very high end Desktop with 256MB RAM and today I have a 2GB RAM Desktop. So, whats the point.
The Linux systems (right word should be kernel) are desiged to use both RAM and swap partition. Swap partition is a partition on Hard disk and is used mostly like RAM. Problem is that HDD access is always slower than RAM access and hence inherently, the system will work little slower even if you have enough RAM not to use swap. The term ”swappiness” is used to determine how the kernel should try to seam-balance between the use of RAM and swap. By default, most of the distro’s have a swappiness of 60. A higher value of swappiness means that the RAM will be swapped out faster.
There are two ways to look at the swappiness:
If the user has a higher swappiness then the used memory will be swapped faster to the swap and thus free’ing the RAM for other useful purposes.
A lower value of swappiness would mean that bloaty applications will not be swapped and thus when the user returns to the application, the application would load faster or rather look faster as there will be no swapping from the swap to the RAM.
I personally keep the swappiness to a value of 100 in the Desktop. But then, anyway I kill firefox as soon as I am done and restart when required.
If you see that the RAM is underutilized or feel that the system performance is not that good then you can tickle with this setting and set it to 10-15. How to do it :
Login as roo (”su -”)
echo 15 > /proc/sys/vm/swappiness
This will take effect immediately, but if you want to change this value permanently then you can do this(again as root):
echo ”sys.vm.swappiness = 10” > /etc/sysctl.conf
So play with your swappiness 🙂