How to Change Hostname on CentOS 7

The hostname will be set at the time of installation of CentOS operating system. If you are creating virtual machine then it will be assigned dynamically at the instance creation time. This tutorial helps you to change a hostname on a CentOS 7 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 differentiates 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. It is used to represent the user. This is stored at /etc/machine-info.
3. transient – A transient hostname is changed in the Linux kernel. It is the same as the static hostname.

It is best practice to use a fully-qualified domain name 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: local.tecnstuff
 Pretty hostname: CentOS7 Server
      Icon name: computer-vm
        Chassis: vm
     Machine ID: 44dddc11e56e403d8053ecdf0b92d462
        Boot ID: c299757e3c8145e09eb2d55172189a24
 Virtualization: kvm
 Operating System: CentOS Linux 7 (Core)
    CPE OS Name: cpe:/o:centos:centos:7
         Kernel: Linux 3.10.0-957.5.1.el7.x86_64
   Architecture: x86-64

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

Change the Hostname using hostnamectl#

In CentOS 7 system, we can use hostnamectl command to change the hostname. 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 local.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

Change the Hostname by Edit /etc/hosts file#

You also can change hostname by changing in /etc/hosts file. Open /etc/hosts file using your favorite text editor:

sudo nano /etc/hosts

In file, change the hostname as per you choice at line that begins with 127.0.0.1

Save and close file. For this method you need to restart your CentOS system.

Verify Hostname#

After changed using second method, you can again check hostname using hostnamectl command and now it should output with new hostname as below:

Static hostname: server.tecnstuff.net
 Pretty hostname: TecNStuff's Server
      Icon name: computer-vm
        Chassis: vm
     Machine ID: 44dddc11e56e403d8053ecdf0b92d462
        Boot ID: c299757e3c8145e09eb2d55172189a24
 Virtualization: kvm
 Operating System: CentOS Linux 7 (Core)
    CPE OS Name: cpe:/o:centos:centos:7
         Kernel: Linux 3.10.0-957.5.1.el7.x86_64
   Architecture: x86-64

As you can see above the hostname is successfully changed from local.tecnstuff to server.tecnstuff.net and also Pretty hostname changed from CentOS7 Server to TecNStuff's Server.

Conclusion#

You learned how to change the hostname on CentOS 7 using different methods. If you face any issues you can leave a comment below.