Changing or setting hostname on Ubuntu 18

How to easily change the hostname on your Ubuntu VPS server, this will work with Ubuntu 16.04, 18.04, 19.10 and 20.04.

Use hostnamectl to view the system hostname and id related information

hostnamectl check hostname ubuntu
hostnamectl output

Here you can see that aus is my hostname.

Changing the hostname

To change  a servers system hostname in Ubuntu 18 or the like use:

sudo hostnamectl set-hostname NEWHOSTNAME

Where NEWHOSTNAME will be the new set hostname.

Next edit the hosts file by running:

sudo nano /etc/hosts

You want to change the old hostname to the new one OR set the new hostname to the correct ipv4.       localhost
144.XX.XXX.XX   hostnamehere

Note 144.XX.XXX.XX has been edited from the real ipv4 address.

Shift + x and then press y to save this new configuration.

Run hostnamectl again to check that the hostname change was successful.