How To Add Swap Space on Ubuntu 18.04
Swap is a space on a disk that is used when the amount of physical RAM memory is full. When a Linux system runs out of RAM, inactive pages are moved from the RAM to the swap space. Swap space can take the form of either a dedicated swap partition or a swap file.
In most cases when running Ubuntu on a virtual machine a swap partition is not present so the only option is to create a swap file….
Linux Tips, Tricks and Tutorials on Linuxize
You might also like to check Linux Cat Command