Swap File for Ubuntu 20.04
Setup swap file on Ubuntu Linux 20.04
Download Ubuntu 20.04 (Focal Fossa) from here and install it.
Check If Swap File Is Already Installed
Some installations may already have a swap file setup. Issue this command in the Terminal:
sudo free -h
The output should look something like this if one is not configured:
total used free shared buff/cache available Mem: 475Mi 155Mi 6.0Mi 0.0Ki 313Mi 298Mi Swap: 0B 0B 0B
Create a Swap File
Create a 4 GiB swap file in the root directory with fallocate:
sudo fallocate -l 4G /swapfile
Should fallocate not be available, use dd.
sudo dd if=/dev/zero of=/swapfile bs=1k count=2048k
Allow Only ROOT User Access to the Swap File
Only the root user should be accessing the newly created swap file. Issue command:
sudo chmod 600 /swapfile
Make the New File the Swap File
Use mkswap as follows:
sudo mkswap /swapfile
Activate the Swap File
Use swapon as follows:
sudo swapon /swapfile
Edit the /etc/fstab File
Use nano as follows to modify this file to only have one line:
sudo nano /etc/fstab
This file should have a line reading this:
/swapfile swap swap defaults 0 0
Verify the Installation
Use free to check the swapfile
sudo free -h
The output should look something like this:
total used free shared buff/cache available Mem: 475Mi 155Mi 6.0Mi 0.0Ki 313Mi 298Mi Swap: 4.0Gi 10Mi 4.0Gi