I've noticed that the "preferred" method of setting the system hostname is fundamentally different between Red Hat/CentOS and Debian/Ubuntu systems. CentOS documentation and the RHEL deployment guide say the hostname should be the FQDN: HOSTNAME=<value>, where <value> should be the Fully Qualified Domain Name (FQDN), such as hostname.example.com, but can be whatever hostname is necessary. The RHEL