This blog entry is taken in part from the  Integrating PNP (PNP is not Perfparse) with CentOS 4.x / Nagios 2.x from NagiosWiki and the book Nagios 2nd Edition from No starch Press.

1. What is PNP4Nagios?
PNP4Nagios (English) is an addon to nagios which analyzes performance data provided by plugins and stores them automatically into RRD-databases

2. Which version will you be covering?
I’ll be using on the pnp4nagios 0.4.x which fit into CentOS 5.x quite well as it does not need to incorporate additional newer components which might break existing dependencies.
Download the pnp4nagios 0.4x from the download website

3. What prerequisites I need?
Install rrdtools
Make sure you have the RPMForge Repository installed. For more information, get more information at LinuxToolkit (Red Hat Enterprise Linux / CentOS Linux Enable EPEL (Extra Packages for Enterprise Linux) Repository).

# yum install rrdtool

4. Download and configure

# wget http://sourceforge.net/projects/pnp4nagios/files/PNP/pnp-0.4.14/pnp-0.4.14.tar.gz/download
# tar -zxvf pnp-0.4.14.tar.gz # cd pnp-0.4-14
# ./configure --sysconfdir=/etc/pnp --prefix=/usr/share/nagios

(For more configuration of ./configure, see ./configure –help)
Output is as followed:

*** Configuration summary for pnp 0.4.14 05-02-2009 ***
General Options:
------------------------- -------------------
Nagios user/group:  nagios nagios 
Install directory:  /usr/share/nagios 
HTML Dir:           /usr/share/nagios/share
Config Dir:          /etc/pnp 
Location of rrdtool binary: /usr/bin/rrdtool Version 1.4.4
RRDs Perl Modules:  FOUND (Version 1.4004)
RRD Files stored in:   /usr/share/nagios/share/perfdata 
process_perfdata.pl Logfile: /usr/share/nagios/var/perfdata.log
Perfdata files (NPCD) stored in: /usr/share/nagios/var/spool/perfdata/

Review the options above for accuracy. If they look okay,
type 'make all' to compile.

# make all
# make install

If there are failure for make or make install, you may not have installed gcc-c++ tool to compile.

# yum install gcc-c++

Create soft links

# ln -s /usr/share/nagios/share /usr/share/nagios/pnp

5. Passing Performance Data to the PNP data collector.
To switch on the performance data processing

# PROCESS PERFORMANCE DATA OPTION
# This determines whether or not Nagios will process performance
# data returned from service and host checks.  If this option is
# enabled, host performance data will be processed using the
# host_perfdata_command (defined below) and service performance
# data will be processed using the service_perfdata_command (also
# defined below).  Read the HTML docs for more information on
# performance data.
# Values: 1 = process performance data, 0 = do not process performance data

process_performance_data=1

# HOST AND SERVICE PERFORMANCE DATA PROCESSING COMMANDS
# These commands are run after every host and service check is
# performed.  These commands are executed only if the
# enable_performance_data option (above) is set to 1.  The command
# argument is the short name of a command definition that you
# define in your host configuration file.  Read the HTML docs for
# more information on performance data.

host_perfdata_command=process-host-perfdata
service_perfdata_command=process-service-perfdata

5a. Switching on the process-service-perfdata

(From inside Nagios configuration directory usually /etc/nagios/)

# cd objects
# vim commands.cfg

define command {
  command_name    process-service-perfdata
  command_line    /usr/bin/perl /usr/share/nagios/libexec/process_perfdata.pl
}

define command {
  command_name    process-host-perfdata
  command_line    /usr/bin/perl /usr/share/nagios/libexec/process_perfdata.pl -d HOSTPERFDATA
}

6. Final check

# cd /etc/nagios
# nagios -v nagios.cfg
(Check for any error. If there is no error, restart the service)
# service nagios restart

(Restart httpd)
# service httpd restart

7. Take a look at the graph!

http://YourServerIPAddres.org/nagios/share/

This Blog entry is modified from Check Disk IO via NRPE from Nagios Wiki

1. What is check_diskio?
check_diskio is a simple Nagios plugin for monitoring disk I/O on Linux 2.4 and 2.6 systems.

2. Where do I get information and download check_diskio?
Got to http://freshmeat.net/projects/check_diskio/

3. Installation Guide
A. Ensure you install the perl package. You will need perl 5.8.x and required modules. You need to install RPMforge Repository (From Linux Toolkit Blog)

At the Client Machine.

# yum install perl

# tar -zxvf check_diskio-3.2.2.tar.gz
# cd check_diskio-3.2.2

# less INSTALL (Read the INSTALL Readme file)
# perl Makefile.PL INSTALLSCRIPT=/usr/lib64/nagios/plugins
(You will see a list of warnings of prerequisites)

B. Install the prerequisites Perl-Modules. Here may not be completed lists.

# yum install perl-Nagios*
# yum install perl-List*
# yum install perl-Readonly*
# yum install perl-Number-Format
# yum install perl-File-Slurp*
# yum install perl-Array-Unique

C. Finally compile

# perl Makefile.PL INSTALLSCRIPT=/usr/lib64/nagios/plugins
# make
# make install
(You will see the check_diskio at /usr/lib64/nagios/plugins)

D. Edit the nrpe.cfg file on the client machine. If you have not download nagios nrpe plugins, just do a

# yum install nagios-nrpe

D1. Edit /etc/nagios/nrpe.cfg on the client machine,

# vim /etc/nagios/nrpe.cfg

command[check_diskio]=/usr/lib64/nagios/plugins/check_diskio --device=/dev/sda -w 200 -c 300

At the Server, just make sure you install the nagios nrpe plugins like D. Finally to ensure that the remote server plugins are ok, do a test at Nagios Server

# cd /usr/lib64/nagios/plugins

# ./check_nrpe -H remote-server -c check_diskio
CHECK_DISKIO OK - sda 194 sectors/s | WRITE=194;200;300 READ=0;200;300 TOTAL=194;200;300

Horray It is done!