How to Fix error 'Could not determine the server's fully qualified domain name, using 127.0.0.1 '

Problem:

[root@spa ~]# service httpd start
Starting httpd: httpd: Could not determine the server's fully qualified domain name, using 127.0.0.1 for S erverName
                                                           [  OK  ]
[root@spa ~]#

solution:

Edit /etc/httpd/conf/httpd.conf
and search for ServerName and add
ServerName localhost