Changing Hostname Debian
Debian based systems use the file /etc/hostname to read the hostname of the system at boot time and set it up using the init script /etc/init.d/hostname.sh
So on a Debian based system we can edit the file /etc/hostname and change the name of the system and then run:
To make the change active. The hostname saved in this file (/etc/hostname) will be preserved on system reboot (and will be set using the same script we used hostname.sh).