Debian Linux: Change Hostname / Computer Name Permanently

To change the hostname of a Debian system permanently, you can follow these steps:

1. Open the /etc/hostname file using a text editor such as nano:

sudo nano /etc/hostname

2. Replace the current hostname with the desired hostname. For example, if you want to change the hostname to "new-hostname", the file should contain only the following line:

new-hostname

3. Save the file and exit the text editor.

4. Open the /etc/hosts file:

sudo nano /etc/hosts

5. Find the line that contains the current hostname, and replace it with the new hostname. For example, if the current hostname is "old-hostname", you should replace it with "new-hostname".

6. Save the file and exit the text editor.

7. Run the hostname command to set the hostname immediately:

sudo hostname new-hostname

8. Reboot the system for the changes to take effect permanently:

sudo reboot

After rebooting, your system's hostname will be changed to the new hostname. You can verify the hostname by running the hostname command.