Add 2GB swap on online vps

sudo fallocate -l 2G /swapfile 
sudo chmod 600 /swapfile 
sudo mkswap /swapfile 
sudo swapon /swapfile 
sudo cp /etc/fstab /etc/fstab.bak 
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab