A computer hostname is simply a unique name of the computer or server that is assigned such that it can be uniquely identify that server in the specific network.

By default, the server hostname is set in the installation process. However, you can change it anytime after the installation as you like.

In this tutorial, we will learn how to change the hostname of the CentOS 7 Linux server CentOS 7 in just a few steps.

Checking the Current Hostname

In the CentOS Linux system, you may use the following command to check the current hostname



The output would show the system hostname(Statis hostname) in the image below:



The Static hostname is the unique machine name used to identify the computer or server in the network. In Linux system, this hostname would also be stored in the system file: /etc/hostname

Alternatively, you may also use the following command to display the server hostname:





Besides, the host name is also stored in the system file: /etc/hostname. So you can simply display the hostname by the following command:

Server Hostname General Rules

In the CentOS Linux, you are recommended to use a fully qualified domain name(FQDN) as the system hostname. The FQDN usually consists of the hostname and the domain name. Besides, the hostname you are going to use needs to comply with the following rules:

Hostnames should be descriptive
Hostnames can contain numbers from 0 to 9
Hostnames can contain lower-case letters a to z
Hostnames can contain periods(.) and hyphens(-)
Hostnames must between 2 and 63 characters long
Hostnames must be start and end with a letter or number

How to Change the Server Hostname

To change the server hostname on CentOS Linux, you can use the following command:

For example, if you want to change the hostname to: "centos7.rocknets.com". You can try the following command:

Then reboot the machine.

After the machine is reboot, you may just check with: hostnamectl, and you will find that the host name is changed successfully.

Conclusion

This tutorial explains how to change the hostname on CentOS 7 Linux system. The steps are straightforward and easy to complete. you should be able to change the hostname on your Linux machine succesfully. Let's try it out!