Debian Linux: Change Hostname / Computer Name Permanently

To change the hostname (computer name) on a Debian Linux system permanently, you can follow these steps:

Open the /etc/hostname file:
```
sudo nano /etc/hostname
```
Replace the existing hostname with your desired hostname. For example:
```
mynewhostname
```
Save and close the file.
Open the /etc/hosts file:
```
sudo nano /etc/hosts
```
Find the line that contains your current hostname and replace it with your new hostname. For example, if the line was:
```
127.0.1.1 oldhostname
```
it should now be:
```
127.0.1.1 mynewhostname
```
Save and close the file.
Restart your system to apply the changes:
```
sudo reboot
```

rnAfter the system restarts, you can verify that the hostname has been changed by running the following command:

hostname

The output should be your new hostname.