Allocate swap file, when server RAM GB is low to remove mysql errors

 sudo fallocate -l 2G /swapfile || sudo dd if=/dev/zero of=/swapfile bs=1M count=2048
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

# optional but recommended
echo 'vm.swappiness=20' | sudo tee /etc/sysctl.d/99-swappiness.conf
sudo sysctl -p /etc/sysctl.d/99-swappiness.conf

free -h
swapon --show