Change hostname in Ubuntu Linux

When we first install a new Operating System one of the typical request of the installation process is to set the hostname.

To change the hostname in Ubuntu Linux system, you can follow different procedures.

Editing system configuration files

Edit the file /etc/hostname using the vi editor. Modify the old name and set the new one.

$ sudo vi /etc/hostname

Edit the file /etc/hosts and replace any ocurrence of the old name with the new one.

$ sudo vi /etc/hosts

Reboot the system to make the changes to take effect.

$ sudo reboot

As in the previous method, it is also needed to edit some files, but also to use the hostname command to set the new hostname without reboot.

$ sudo vi /etc/hostname
$ sudo vi /etc/hosts
$ sudo hostname new-server-name

This is the easiest method, but not valid for all Ubuntu releases. It only works from Ubuntu 16.04 and above.

$ hostnamectl
$ sudo hostnamectl set-hostname new-server-name
$ hostnamectl