How to Change the Hostname on Ubuntu Server

To change the hostname on an Ubuntu server, you need to edit two files:

1. /etc/hostname
2. /etc/hosts

You'll need root permissions to edit. So, for #1:

$ sudo vim /etc/hostname

Note: Replace vim with the editor of your choice.

This file should just contain your hostname, so you can change the old name to the new name, then save and quit.

Next file:

$ sudo vim /etc/hosts

You probably see something like this near the top of the file:

/etc/hosts

127.0.0.1       localhost
127.0.1.1       old_server_name

# ...

Here change what you find at old_server_name to your new hostname.

And reboot.

$ sudo reboot