Upgrade Nagios 3 to Nagios 4

If you are already running an older version of Nagios

you can upgrade it anytime you just need to download the latest tar archive of it and configure it

[root@nagios ]# service nagios stop

[root@nagios ]# wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.2.0.tar.gz

[root@nagios ]# tar -zxvf nagios-4.2.0.tar.gz

[root@nagios ]# cd nagios-4.2.0

[root@nagios ]# ./configure

[root@nagios ]# make all

[root@nagios ]# make install

[root@nagios ]# service nagios start