If when you start Apache you get the following error:
Starting httpd: httpd: Could not reliably determine the server’s fully qualified domain name, using hostname.domainname.com for ServerName
[ OK ]
You can correct the problem by setting the ServerName in the /etc/httpd/conf/httpd.conf. By default ServerName is not set in the httpd.conf. If you search for the following line:
You can uncomment it and set it accordingly.
Then, just restart Apache and you’ll be up and running.
# service httpd restart