Swap space is fake memory that is actually disk space. The purpose of swap space is to be emergency overflow memory. Normally, if your server runs out of memory, the Linux kernel has to decide which processes to kill to free up memory. Often it’s MySQL that gets killed first.
View existing Swap usage
You can view your existing Swap memory usage and details by the following commands. Make sure you logged in as root.
Remember: The swap space shown from the above command does not mean your server is actively swapping at the moment; swap space is only used when your server runs out of memory. This number can be cleared by rebooting your server.
Increase or add Swap
Type the following commands one by one as root.
swapoff -a fallocate -l 1G /swapfile chmod 600 /swapfile mkswap /swapfile swapon /swapfile sudo cp /etc/fstab /etc/fstab.bak echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab
That’s it. You are done. To verify the new swap size, just type “free -m” again.