Creates a Swap file in Ubuntu 14.04, useful for increase memory in virtual machines

swapfile.sh

#!/bin/sh

# Creates swap file
sudo dd if=/dev/zero of=/swapfile bs=1G count=1 &&
sudo chmod 600 /swapfile &&
sudo mkswap /swapfile &&
sudo swapon /swapfile;

# Remove swap file
sudo swapoff /swapfile && 
sudo rm -rf /swapfile

This creates a 1Gb Swap partition file. You should have at least 1Gb free RAM on your system.