Updating Ubuntu Hostname After Cloning a Disk

Step 1: Change the Hostname

Update the hostname using the hostnamectl command:

sudo hostnamectl set-hostname NEW_HOSTNAME

Or Update /etc/hostname

Edit the file manually:

sudo nano /etc/hostname

Replace the existing hostname with NEW_HOSTNAME, then save (CTRL + X, then Y, then ENTER).

Step 3: Update /etc/hosts

Edit the /etc/hosts file:

sudo nano /etc/hosts

Replace any instances of the old hostname with NEW_HOSTNAME. Ensure the file contains:

127.0.0.1   localhost
127.0.1.1   NEW_HOSTNAME

Save and exit.

After completing these steps, the system will use the new hostname upon reboot.