How to Change Hostname on CentOS

By tutsfx Last updated Jun 5, 2020

CentOS Supported Versions

This guide applies to:

CentOS 8
CentOS 7

Introduction

When creating a new Vultr VPS, you can set the Server Hostname before deployment. If you skip this step or decide to rename your server later, you’ll discover that changing the server hostname from the Customer Portal also performs a fresh reinstall of the entire server.

Follow this guide if you need to change the server hostname without reinstalling.

Examples

This guide uses olddog for the old hostname and newtricks for the new hostname.

1. Check the Current Hostname

Check the hostname with hostname

hostname
olddog

You can also use

hostnamectl

 $ hostnamectl 
 Static hostname: olddog
       Icon name: computer-vm
         Chassis: vm
      Machine ID: 4a92996cd47145f1ba4b8ad1420bad64
         Boot ID: 4515953cc80846f4a9078a7916db3819
  Virtualization: kvm
Operating System: CentOS Linux 8 (Core)
     CPE OS Name: cpe:/o:centos:centos:8
          Kernel: Linux 4.18.0-147.8.1.el8_1.x86_64
    Architecture: x86-64

2. Change Hostname

Change the hostname to newtricks.

sudo hostnamectl set-hostname newtricks

3. Update /etc/hosts

Use your favorite text editor to change any instances of your old hostname to the new hostname in /etc/hosts. If you have a DNS name pointed to this instance, it’s a best practice to also set that name here.

sudo nano /etc/hosts

From:

127.0.0.1 olddog
::1       olddog

To:

127.0.0.1 newtricks newtricks.example.com
::1       newtricks newtricks.example.com

4. Confirm the Change

Reboot the server.

Test your change with hostnamectl and hostname.

$ hostnamectl
 Static hostname: newtricks
       Icon name: computer-vm
         Chassis: vm
      Machine ID: 4a92996cd47145f1ba4b8ad1420bad64
         Boot ID: 4515953cc80846f4a9078a7916db3819
  Virtualization: kvm
Operating System: CentOS Linux 8 (Core)
     CPE OS Name: cpe:/o:centos:centos:8
          Kernel: Linux 4.18.0-147.8.1.el8_1.x86_64
    Architecture: x86-64

$ hostname
newtricks
$ hostname -a
newtricks.example.com

Update DNS

Your server hostname is changed and ready to use. This procedure does not change your DNS name, and you’ll need to perform those steps at your domain registrar.