Story on nagios setup and my web server

I tried to installed Nagios on my web server today, hoping it could help me monitoring the server and report any problem it can detect.

After I followed instruction on:

http://nagios.sourceforge.net/docs/3_0/quickstart-fedora.html

/usr/sbin/usermod -G nagcmd apache

to change group of apache, my server went completely down! Apache refused me from accessing any pages on mysite.

I initially thought it was related to SELinux setting, but later I figured, my SELinux is not enabled.

After reviewing secure log, I noticed apache was removed from the following two groups:
apache
psaserv

By adding it back to those groups, my sever is running OK again.

Well, be careful when you change any group setting :(