Here’s a quick step-by-step procedure on how to install Nagios Monitoring in CentOS 5. The installation is straightforward. You just have to copy and paste it to your SSH Terminal.
yum update
yum install httpd php
yum install gcc glibc glibc-common
yum install gd gd-devel
/usr/sbin/useradd -m nagios
passwd nagios
set nagios as password (I used nagios)
/usr/sbin/groupadd nagcmd
/usr/sbin/usermod -a -G nagcmd nagios
/usr/sbin/usermod -a -G nagcmd apache
mkdir ~/downloads
cd ~/downloads
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.1.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz
tar xvzf nagios-3.2.1.tar.gz
cd nagios-3.2.1
./configure –with-command-group=nagcmd
make all
make install
make install-init
make install-config
make install-commandmode
make install-webconf
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
set password for nagiosadmin = this is the webui
service httpd restart
cd ~/downloads
tar xvzf nagios-plugins-1.4.11.tar.gz
cd nagios-plugins-1.4.11
./configure –with-nagios-user=nagios –with-nagios-group=nagios
make
make install
chkconfig –add nagios
chkconfig nagios on
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
chmod 777 /usr/local/nagios/var/rw/nagios.cmd
service nagios start