How to Change Hostname on Ubuntu 20.04

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Displaying the Current Hostname

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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: 20111e34366400515e16e9f15f909808
                     Boot ID: c10547c46d214b1a96117029642dd499
        Virtualization: kvm
    Operating System: Ubuntu 20.04 LTS
                        Kernel: Linux 5.4.0-26-generic
            Architecture: x86-64

Changing the System Hostname

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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:

root@crowncloud:~# cat /etc/hosts
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

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

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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: 20111e34366400515e16e9f15f909808
                     Boot ID: c10547c46d214b1a96117029642dd499
        Virtualization: kvm
    Operating System: Ubuntu 20.04 LTS
                        Kernel: Linux 5.4.0-26-generic
            Architecture: x86-64
root@vps:~#