How to change the hostname of a linux box

You have to make two changes:

1. vi /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=linux.justanexample.com

2. vi /etc/hosts

192.168.2.1 linux.justanexample.com linux

The IP adress given is just an example. You can use whatever IP is assigned to you by your ISP also. Reboot and you have new hostname for your box: linux.justanexample.com