How to Change Hostname on CentOS 8

This tutorial guides you through the process of change a hostname on a CentOS 8 system.

The hostname is set at the time when the CentOS operating system is installed or if you are spinning up a virtual machine it is dynamically assigned to the instance at startup.

This tutorial helps you to change a hostname on a CentOS 8 system.

Prerequisites#

Before starting, make sure you are logged in with non-root user with sudo privileges.

Change Hostname on CentOS#

By assigning a hostname you can identify a system on a network. It is important that you shouldn’t have same hostname on a same network.

There are three types of hostnames as below:

1. static – This is the most important type of hostname. This is used to identify a particular server between machines on network. It’s stored at /etc/hostname file. For example, TecNStuff’s Server.
2. pretty – This is more user-friendly and can use more characters and punctuation as per UTF8 character set. It represents the user. For exampleTecNStuff's System.
3. transient – A transient hostname is changed in the Linux kernel. It is the same as the static hostname. Transient hostnames can be set/update by DHCP or mDNS at runtime.

It is best practice to use a fully-qualified domain name (FQDN) for both static and transient hostnames like server.tecnstuff.net.

Check Existing Hostname#

Run below command to check the existing hostname for your system:

hostnamectl

Static hostname: localhost.tecnstuff
      Icon name: computer-vm
        Chassis: vm
     Machine ID: 31dcdc11e56e403c8053ecdf0b92d452
        Boot ID: e289757e3c8145e09eb4d55172189a14
 Virtualization: kvm
 Operating System: CentOS Linux 8 (Core)
    CPE OS Name: cpe:/o:centos:centos:8
         Kernel: Linux 4.18.0-80.7.1.el8_0.x86_64
   Architecture: x86-64

As you can see on above output, here current hostname name is localhost.tecnstuff.

Change the Hostname using hostnamectl#

In CentOS 8 system, we can use hostnamectl command to change the hostname and related settings. Following is the basic syntax to change hostname:

sudo hostnamectl set-hostname NEW_HOST_NAME

sudo hostnamectl set-hostname server.yourdomain.com
sudo hostnamectl set-hostname server.yourdomain.com --static
sudo hostnamectl set-hostname "Pretty HostName" --pretty
sudo hostnamectl set-hostname server.yourdomain.com --transient

You can run command as below to change hostname:

sudo hostnamectl set-hostname server.tecnstuff.net

Here we changed hostname from localhost.tecnstuff to server.tecnstuff.net using hostnamectl command. Now the hostname is server.tecnstuff.net for server, you can check it again using hostnamectl command.

Same as you can set pretty name for server using below command:

sudo hostnamectl set-hostname "TecNStuff's Server" --pretty

Verify Hostname#

To verify that the hostname changed successfully, use hostnamectl command and now it should show output with new hostname as below:

Static hostname: server.tecnstuff.net
 Pretty hostname: TecNStuff's Server
      Icon name: computer-vm
        Chassis: vm
     Machine ID: 31dcdc11e56e403c8053ecdf0b92d452 
        Boot ID: e289757e3c8145e09eb4d55172189a14
 Virtualization: kvm
 Operating System: CentOS Linux 8 (Core)
    CPE OS Name: cpe:/o:centos:centos:8
         Kernel: Linux 4.18.0-80.7.1.el8_0.x86_64
   Architecture: x86-64

As you can see above the hostname is successfully changed from localhost.tecnstuff to server.tecnstuff.net and also Pretty hostname is TecNStuff's Server.

Conclusion#

On CentOS system, you can can use the hostnamectl command to change hostname and set a new name as well.

If you face any issues you can leave a comment below.