Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on the plug and play capabilities. After completing an installation a high number of monitoring plugins will be playing with no more effort.
Credit goes to munin for developing such a good monitoring tool.
Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine “what’s different today” when a performance problem crops up. It makes it easy to see how you’re doing capacity-wise on any resources.
Munin uses the excellent RRDTool (written by Tobi Oetiker) and the framework is written in Perl, while plugins may be written in any language. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for data. It then stores the data in RRD files, and (if needed) updates the graphs. One of the main goals has been ease of creating new plugins (graphs).
This article will help you to install Munin on your system.
Step 1: Set Up EPEL Repository
First, we need to add an epel repository in our system. Use one of the following commands to install as per system architecture.
CentOS/RHEL 6, 32 Bit (i386):
# rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
CentOS/RHEL 6, 64 Bit x86_64):
# rpm -Uvh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
CentOS/RHEL 5, 32 Bit (i386):
# rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
CentOS/RHEL 5, 64 Bit (x86_64):
# rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
Step 2: Install Munin Packages
Use following command to install Munin and required packages
# yum –enablerepo=epel install munin munin-node rrdtool httpd
Step 3: Configure Apache
By default Munin creates Apache configuration file /etc/httpd/conf.d/munin.conf. Edit Munin Apache configuration file and add following content.
# vim /etc/httpd/conf.d/munin.conf
Alias /munin /var/www/html/munin
<Directory /var/www/html/munin>
    Options FollowSymLinks
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>
<directory /var/www/html/munin>
        AuthUserFile /etc/munin/munin-htpasswd
        AuthName “Munin”
        AuthType Basic
        require valid-user
        ExpiresActive On
        ExpiresDefault M310
</directory>
ScriptAlias /munin-cgi/munin-cgi-graph /var/www/cgi-bin/munin-cgi-graph
Create munin htpasswd file using following command
# htpasswd -cm /etc/munin/munin-htpasswd muninadmin
New password:
Re-type new password:
Above created login details will be required to access Munin web interface.
Step 4: Restart Services
First, start Munin node service and configure to autostart on system boot.
# /etc/init.d/munin-node start # chkconfig munin-node on Restart Apache service # service httpd restart[/box]
Step 5: Access Munin Web Interface
Open the following URL in the browser to access Munin web interface. Change IP/domain as per your setup.
http://localhost/munin