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Monitoring

I found Munin much more useful than Nagios for monitoring a single server. This guide will show you how to set up a single Munin instance that generates pretty graphs with cron and is accessible via Munin’s web interface.

Get Munin’s dependencies

You will need EPEL, a webserver (I’ll use Apache here) and some Munin packages.

EPEL Repo:

Get the latest EPEL repo from here and install. example:

# rpm -i http://mirrors.ptd.net/epel/6/i386/epel-release-6-8.noarch.rpm

Munin Packages:

# yum install munin munin-node httpd

Start Munin Service and Enable on boot

# service munin-node start
# service httpd start
# chkconfig munin-node on
# chkconfig httpd on

Configure Web Interface

Setup a user and password to access the web interface.

# htpasswd /etc/munin/munin-htpasswd <INSERT A USER NAME HERE>

Navigate to web interface: http://<server ip>/munin

If you don’t see the UI below, but instead see a directory listing, give Munin a few minutes to generate data. By default it will generate graphs every 5 minutes. I usually edit /etc/cron.d/munin such that graphs are generated every hour as I use it more for historical purposes and if I need immediate insight I just use htop.

munin-overview

Some example graphs:

munin-graphmunin-graph-cpu