1. Multiply the Mb of swap that you want by 1024. For example, a 256 MB swap file would give 262144.
2. As root or prefacing the commands with sudo, type the following commands where <size> is the number you got from Step 1:

      dd if=/dev/zero of=/swapfile bs=1024 count=<size>
      mkswap /swapfile
      swapon /swapfile

• The above commands create the file, make the file a swapfile, and then turn it on. You should now see your additional swap using the commands top or free.

• To enable your swapfile during normal boot, edit /etc/fstab to include:

      /swapfile               swap                    swap    defaults        0 0