How to change hostname in Linux

Here is an example of changing the hostname in Linux.

First, switch to the root user or add “sudo” before the commands.
Let’s see the current hostname:

hostname
uname -n
sysctl kernel.hostname

Let’s see what hostname is specified in the configuration file:

cat /etc/hostname
cat /etc/hosts

To change the hostname, use the command, it changes it in /etc/hostname, as well as other places:

hostnamectl set-hostname IXNFO

If necessary, add a new hostname here:

nano /etc/hosts

In order for the new hostname to take effect, you can reboot the server or change it immediately:

hostname NEW_HOSTNAME

Or so:

sysctl kernel.hostname=NEW_HOSTNAME

Both previous commands set the hostname before the system is restarted, and after the startup the system takes the hostname from the file /etc/hostname.