If I set a new linux copy up, and then set the hostname in /etc/sysconfig/network (CentOS) is that my FQDN?
Solution 1:
You'll also need to change it in /etc/hosts. Once you've done this, a simple "service network restart" should sort you out.
Yes, your FQDN is your full domain name, complete with the last dotted part(s) (i.e., for a server named "fancypants", while you might refer to it as "fancypants" casually, its FQDN is actually "fancypants.somedomain.net"). Type "hostname" to see what your server thinks it is.