kazulog@webserver:~$ sudo hostname dbserver
kazulog@webserver:~$ hostname
dbserver
kazulog@webserver:~$ hostnamectl | head -3
Transient hostname: dbserver
   Static hostname: webserver
   Pretty hostname: Kazulog Web Server
kazulog@webserver:~$ cat /etc/hostname
webserver
kazulog@webserver:~$ uname -n
dbserver