How to Change Hostname on Debian 9

This tutorial outlines steps to change hostname on Debian 9 system. The hostname will be set at the time of installation of Debian operating system. If you are creating a virtual machine, it will dynamically assign when instance created.

Prerequisites#

Before starting with tutorial, ensure that you are logged in as a non-root user with sudo privileges.

Change Hostname on Debian#

By assigning a hostname you can identifies a system on a network. You must make sure that there shouldn’t have same hostname on a same network.

Get Current Hostname#

At first, you need to check current hostname. To get the current hostname, run the below command:

hostnamectl

  Static hostname: local.tecnstuff
        Icon name: computer-vm
          Chassis: vm
       Machine ID: 287b816ad03c4f429f7bb49501983e1c
          Boot ID: 7fd5cca4dd5c41f6ac53214e11fa3f57
   Virtualization: oracle
 Operating System: Debian GNU/Linux 9 (stretch)
           Kernel: Linux 4.9.0-8-amd64
     Architecture: x86-64

In above output you can see that the current hostname is local.tecnstuff.

Changing the Hostname using hostnamectl#

In Debian 9, there are multiple methods to change hostname. First one is change the hostname using hostnamectl command. Following is the basic syntax to change hostname:

sudo hostnamectl set-hostname NEW_HOST_NAME

You can run command as below to change hostname:

sudo hostnamectl set-hostname server.tecnstuff.net

We changed the 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.

Change the Hostname by Edit /etc/hosts file#

Another method to change hostname is to edit /etc/hosts file manually. Open /etc/hosts file using your favorite text editor:

sudo nano /etc/hosts

Inside the 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 system.

Verify Hostname#

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

  Static hostname: server.tecnstuff.net
        Icon name: computer-vm
          Chassis: vm
       Machine ID: 287b816ad03c4f429f7bb49501983e1c
          Boot ID: 7fd5cca4dd5c41f6ac53214e11fa3f57
   Virtualization: oracle
 Operating System: Debian GNU/Linux 9 (stretch)
           Kernel: Linux 4.9.0-8-amd64
     Architecture: x86-64

As you can see above the hostname is successfully changed from local.tecnstuff to server.tecnstuff.net .

Conclusion#

Finally, you learned how to change the hostname on Debian 9 system using different methods.

If you face any issues or have any suggestions you can leave a comment below.