Changing hostname on RHEL:
1. Change the HOSTNAME line in /etc/sysconfig/network
2. Change the hostname (FQDN and alias) in /etc/hosts
3. Run /bin/hostname new_hostname for the hostname change to take effect immediately.
4. Run /sbin/service syslog restart for syslog to log using the new hostname.
A reboot is not required to change the system hostname.
