How do I Configure Swappiness?

I need a step-by-step, simple and easy way to configure swappiness.

Answer:

• One liner sudo bash -c "echo 'vm.swappiness = 15' >> /etc/sysctl.conf"
• @redanimalwar you also need to run sudo sysctl -p to load the new swappiness value from the sysctl.conf file, otherwise the change just applies on the next reboot.
• The Linux kernel provides a tweakable setting that controls how often the swap file is used, called swappiness.

  A swappiness setting of zero means that the disk will be avoided unless absolutely necessary (you run out of memory), while a swappiness setting of 100 means that programs will be swapped to disk almost instantly.

  Ubuntu system comes with a default of 60, meaning that the swap file will be used fairly often if the memory usage is around half of my RAM. You can check your own system’s swappiness value by running:

  one@onezero:~$ cat /proc/sys/vm/swappiness
  60
  

  As I have 4 GB of RAM I’d like to turn that down to 10 or 15. The swap file will then only be used when my RAM usage is around 80 or 90 percent. To change the system swappiness value, open /etc/sysctl.conf as root. Then, change or add this line to the file:

  vm.swappiness = 10
  

  Apply the change.

  sudo sysctl -p
  

  You can also change the value while your system is still running with:

  sysctl vm.swappiness=10
  

  You can also clear your swap by running swapoff -a and then swapon -a as root instead of rebooting to achieve the same effect.

  To calculate your swap Formula:

  free -m (total) / 100 = A
  
  A * 10
  
  root@onezero:/home/one# free -m
               total       used       free     shared    buffers     cached
  Mem:          3950       2262       1687          0        407        952
  -/+ buffers/cache:        903       3047
  Swap:         1953          0       1953
  

  so total is 3950 / 100 = 39.5 * 10 = 395

  So what it mean is that when 10 % (395 MB) of ram is left then it will start using swap.