This tutorial will guide you through the process of changing the hostname on an Ubuntu 18.04 system.
The hostname is set at the time when the Ubuntu operating system is installed or if you are spinning up a virtual machine it is dynamically assigned to the instance at startup.
The method described in this guide will work without the need of restarting your system.
Although this tutorial is written for Ubuntu 18.04 the same instructions apply for Ubuntu 16.04 and any Ubuntu-based distribution, including Linux Mint and Elementary OS.
Before continuing with this tutorial, make sure you are logged in as a user with sudo privileges.
A hostname is a label that identifies a machine on the network. You shouldn’t use the same hostname on two different machines on a same network.
Display the Current Hostname
To view the current hostname, enter the following command:
As you can see in the image above, the current hostname is set to
Change the Hostname
The following steps outline how to change the hostname in Ubuntu 18.04.
1. Change the hostname using
In Ubuntu 18.04 we can change the system hostname and related settings using the command
For example, to change the system static hostname to
black, you would use the following command:
sudo hostnamectl set-hostname black
hostnamectl command does not produce output. On success, 0 is returned, a non-zero failure code otherwise.
2. Edit the
/etc/hosts file and change the old hostname to the new one.
127.0.0.1 localhost 127.0.0.1 black # The following lines are desirable for IPv6 capable hosts ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters
3. Edit the
cloud-init package is installed you also need to edit the
cloud.cfg file. This package is usually installed by default in the images provided by the cloud providers such as AWS and it is used to handle the initialization of the cloud instances.
To check if the package is installed run the following ls command:
ls -l /etc/cloud/cloud.cfg
If you see the following output it means that the package is not installed and no further action is required.
ls: cannot access '/etc/cloud/cloud.cfg': No such file or directory
If the package is installed the output will look like the following:
-rw-r--r-- 1 root root 3169 Apr 27 09:30 /etc/cloud/cloud.cfg
In this case you’ll need to open the
sudo nano /etc/cloud/cloud.cfg
preserve_hostname and change the value from
# This will cause the set+update hostname module to not operate (if true) preserve_hostname: true
Save the file and close your editor.
Verify the change
To verify that the hostname was successfully changed, once again use the
Static hostname: black Icon name: computer-vm Chassis: vm Machine ID: 6f17445f53074505a008c9abd8ed64a5 Boot ID: 1c769ab73b924a188c5caeaf8c72e0f4 Virtualization: kvm Operating System: Ubuntu 18.04 LTS Kernel: Linux 4.15.0-22-generic Architecture: x86-64
You should see your new server name printed on the console.
In this tutorial, we have shown you how to easily change your Ubuntu server hostname without restarting the machine.
Feel free to leave a comment if you have any questions.