My swap disk keep "unmounting" every time i boot up my laptop

How to lock the swap on, i resized my disk storage recently and i was careful to turn the swap off and then turn it on just like the tutorial , but now everytime i boot up my device , i find that the swap is off. How to turn it on permanently ?

You can:

  1. edit fstab to include the swap
  2. set as boot action the command that turns the swap on
    choose one of these, not both!

Any guides to follow ?
Execute the commands in the second post...
Instead of using xed in the xed admin:///etc/fstab string, use gedit
Or, even better, use the solution in the third post!

I followed the third solution in third comment. and it worked great.
Thanks for help