Change Host Name in Ubuntu Server
added by Johan 1/23/13

You might run into a situation that requires you to change your computer name.

By following these steps, you’ll give your computer a new identity in no time.

1. In a terminal window:
sudo su
enter your password

2. Input the following command:
  nano /etc/hostname

3. The hostname file will open, displaying the current computer name.
Replace the current computer name with the desired new name
(In my case it was site5.northwestmall.com)

5. Click Ctrl-X, then "Y".

6. reboot -h now

7. To check the hostname after a reboot, enter:
hostname
OR
hostname -f
which will show the fully qualified host name