How to Change Hostname on Debian 12

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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@server:~# hostnamectl
 Static hostname: server
       Icon name: computer-vm
         Chassis: vm 🖴
      Machine ID: 79b6eac931d64e9085fadca9e55a908c
         Boot ID: 86564aa1bbfb4455be62a1f348fae14c
  Virtualization: kvm
Operating System: Debian GNU/Linux 12 (bookworm)
          Kernel: Linux 6.1.0-9-amd64
    Architecture: x86-64
 Hardware Vendor: Red Hat
  Hardware Model: KVM
Firmware Version: 1.16.0-3.module_el8.7.0+3346+68867adb
root@server:~#

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 Debian server name.

vi /etc/hosts

Output:

127.0.0.1       localhost
127.0.1.1       crowncloud.net  server

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

Then replace the old name with the new, then save the file and exit.

Debian 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@server:~# hostnamectl
 Static hostname: crowncloud.net
 Pretty hostname: crowncloud production server
       Icon name: computer-vm
         Chassis: vm 🖴
      Machine ID: 79b6eac931d64e9085fadca9e55a908c
         Boot ID: 86564aa1bbfb4455be62a1f348fae14c
  Virtualization: kvm
Operating System: Debian GNU/Linux 12 (bookworm)
          Kernel: Linux 6.1.0-9-amd64
    Architecture: x86-64
 Hardware Vendor: Red Hat
  Hardware Model: KVM
Firmware Version: 1.16.0-3.module_el8.7.0+3346+68867adb
root@server:~#