How to Change Hostname on Ubuntu 21.04
Displaying the Current Hostname
To find out your current system name by running the following command.
hostnamectl
Output:
root@vps:~# hostnamectl
Static hostname: vps.server.com
Icon name: computer-vm
Chassis: vm
Machine ID: 408de4acd0a039b7ebea51f4608a0ab1
Boot ID: bb8ccfc8e2824c569d170a176974495b
Virtualization: kvm
Operating System: Ubuntu 21.04
Kernel: Linux 5.11.0-16-generic
Architecture: x86-64
Changing the System Hostname
Now that you know the current hostname, you can change the hostname by using the following command and Optionally you can also set the pretty hostname as follows.
hostnamectl set-hostname crowncloud.net
hostnamectl set-hostname "crowncloud production server" --pretty
And also /etc/hosts file should be edited to successfully change Ubuntu server name.
vi /etc/hosts
Output:
127.0.0.1 localhost
127.0.1.1 crowncloud.net
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
Then replace the old name with the new, then save the file and exit.
Ubuntu servers might need to install cloud-init. If it is installed you will also need to edit the cloud.cfg file.
apt install cloud-init
Once the cloud-init is installed need to find "preserve_hostname: false" line in the follwoing configuration file "/etc/cloud/cloud.cfg" and change it to true.
vi /etc/cloud/cloud.cfg
preserve_hostname: true
Save the file and exit,
Verify the change
To verify the hostname has been fully changed, enter the "hostnamectl" command:
hostnamectl
Output:
root@vps:~# hostnamectl
Static hostname: crowncloud.net
Pretty hostname: crowncloud production server
Icon name: computer-vm
Chassis: vm
Machine ID: 408de4acd0a039b7ebea51f4608a0ab1
Boot ID: bb8ccfc8e2824c569d170a176974495b
Virtualization: kvm
Operating System: Ubuntu 21.04
Kernel: Linux 5.11.0-16-generic
Architecture: x86-64
root@vps:~#