Summarized commands from 'How To Add Swap Space on Ubuntu 18.04' Digital Ocean Tutorial (https://www.digitalocean.com/community/tutorials/how-to-add-swap-space-on-ubuntu-18-04)

add-swap-space-on-digital-ocean-ubuntu.sh

free -h && \
sudo fallocate -l 1G /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 && \
sudo sysctl vm.swappiness=10 && \
echo 'vm.swappiness = 10' | sudo tee -a /etc/sysctl.conf && \
sudo sysctl vm.vfs_cache_pressure=50 && \
echo 'vm.vfs_cache_pressure=50' | sudo tee -a /etc/sysctl.conf && \
free -h