When you hear Nagios, most people think of their award-winning monitoring software and that is the subject of this article. Nagios is open source software, but there are more options to use Nagios free of charge.
1. Nagios Core – Open Source
Nagios Core, available at nagios.org, is freely available to download, use, and modify. It’s called Core because it uses the same engine that is under the hood of their commercial product, Nagios XI, available at nagios.com. More on that later though. The open source version offers 100’s of free add-ons and the ability to monitor just about anything with an IP address. The core edition has no limitation on the number of monitored devices. Core has been used from everything form monitoring a garden all the way up to looking after the High-End Computing Capability over at NASA. Core’s open nature allows for lots of tinkering and complete control to modify it to suit your needs.
With a ton of control and openness there is also a learning curve. Managing Nagios Core can be difficult for lots of monitored nodes. We used the Core edition in our data center before switching to XI. Managing monitored hosts also meant manually editing 100’s of config files. Many Linux sysadmins may love this approach but we found it too cumbersome. Also, installing Core will mean compiling from source code and will take some time to setup.
2. Nagios XI – Use the Commercial Version of Nagios Free
XI is the commercial version of the already great Core version. The main advantages to Nagios XI are Web Configuration and built in Performance Graphing. Also, you get SNMP Trap Support, easy Configuration Wizards, and a Database Backend. The UI is also just much more polished and integrated than the core. The main disadvantage to using Nagios XI free is that you are limited to 7 total nodes, or hosts. You can monitor more than you may think with 7 hosts though. A host is typically anything with an IP address. Under that, you can monitor unlimited services attached to that host. Theoretically, you could monitor 10,000 individual service checks under one host.
The good news is that the free version can even be used for commercial purposes. Let’s say you have a data center and use Nagios Core to monitor your infrastructure. If the data center goes dark, so does your core server and you wouldn’t be notified. Spend an hour and about $10 a month and you can spin up Nagios XI for free in Amazon AWS. It’s super easy and a cheap insurance policy for when everything else fails. For small projects, this is the best way to run Nagios free.
3. Run a Free Trial
Nagios is very generous with their free trials. They offer 60 days free for most of their products. If you are serious about using their software and may move to their paid version there is a strong possibility that a rep here at MCS can get your trial extended. Contact us to let us know what your specific situation is. Nagios XI runs as a trial by default so use the download link above for this option too. If you have less than 7 hosts it takes about 10 seconds to convert a trial to the free edition that won’t expire.