Posts Taged nagios


Manually Install Nagios XI on Linux, the Easy Way

Installing Nagios XI has one the easiest setups around. While Nagios XI is not officially offered through standard repositories, the process is still so easy. In many cases, when we are starting fresh with a brand new Nagios installation for a customer, our engineers will use the .ova image. This is quick and easy but offers fewer options. When the VMware image is not ideal, we use the method below to manually install Nagios XI on Linux.

    1. Install your preferred Linux OS. Nagios XI is officially supported on CentOS, RHEL, Debian, Ubuntu, and Oracle Linux. We recommend a minimum install with no GUI to optimize performance and decrease your security footprint.
    2. Once your OS is installed, go ahead and make sure it has Internet access and run a full update using yum or apt-get. Restart.
    3. Run this command as root/superuser (you may have to install curl depending on how minimal your install was)
      curl | shThis script will automatically download and install the latest version. Grab a cup of coffee, this will take several minutes.
    4. Once the wall of streaming text stops you should be greeted with a message telling you what URL to use to continue your setup.


Finish Up your Manual Nagios XI Installation via Browser

Now, you can use a web browser to set the Nagios Admin username and password. You can also install a license, activate a free trial, or go straight into the free 7 host mode. Many large organizations we have worked with will have a customized base image of Linux they deploy with custom login servers, security settings, and integrations built-in. This type of customization will work with Nagios but we always recommend that the base OS be as minimal as possible. Custom firewall rules and other security settings may not work without extra configuration.

If your organization would like expert assistance with your Nagios XI deployment, contact MCS for a free quote. We can assist with projects of all sizes. Our Nagios experts can help you manually install Nagios right the first time.

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3-in-1 Nagios XI License

Your Nagios XI License is Actually 3-in-1

As a Nagios featured reseller for North America we have helped organizations large and small procure Nagios XI licenses. The thing about license agreements and usage is that they can be tricky to understand. While the core components of the Enterprise ready Nagios XI are open source, the parts that make XI beautiful to use, and easy to manage are not open source. You can run as many Open Source Nagios Core servers monitoring as many nodes as you desire for free. If you want want support, a more polished UI, and Enterprise grade features it makes sense to use the Nagios XI version made for business.


Buying an Enterprise grade monitoring solution does come with a cost. Depending on the edition and number of nodes (or hosts) being monitored, Nagios XI list price scales to fit the needs of any organization. List price runs anywhere from $1,295 to over $20k for an Unlimited Enterprise edition. We know that for an IT department and management to know the health of their network and services at a glace is well worth the cost. But did you know that when you make a purchase of a Nagios XI license it includes 3 servers in 1?

3 Instances in 1 License

Once you own your license, Nagios allows 3 instances to be installed in your organization. An instance is just a server or VM running a full copy of XI. Here are the 3 allowed uses:

  1. Production – This is your main license that you use day to day and rely on.
  2. Test – Used for testing / lab only. It is recommended that you run this instance to test software upgrades, try new plugins, and proof of concept any new additions or changes before you use them on your production XI.
  3. DR – This instance can possibly be setup in a redundant data center and can monitor everything that production does. Just make sure you are not using it to monitor new nodes that are not covered by your production instance. That would require another license.

Just use your license key on each of the 3 instances. If you have activation problems, make sure you are only using 3 instances and if so, contact Nagios and they will make sure you are activated.

We’ll help you find the right Nagios product at the right price.  Contact MCS to get a quote.

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Nagios Chicago Meetup

Join our Nagios Meetup Group for Chicago

MCS has started the official Nagios Community Meetup Group for the Chicago region. This is the official Nagios Meetup Chicago group part of a network Nagios Community Meetup Groups worldwide. We will hold events and have discussions about Nagios and monitoring in general.

Nagios Meetup Chicago

Chicago, IL
18 Members

This is a new group we created because there are so many Nagios users in Chicago and surrounding areas. It’s always great to hear the unique use-cases people have with Nagios….

Next Meetup

How to monitor virtually anything / Beyond the server room

Tuesday, Oct 27, 2020, 5:00 PM
2 Attending

Check out this Meetup Group →

Virtual Nagios Meetup Chicago Through the End of 2020

Originally, these meetup events were meant to be held in person but obviously, that is no longer possible to do safely. We hope to hold live Nagios meetup events in late 2021. For now, our venue will be Zoom and they will be free to attend. Our goal is to hold casual presentations to bring together Nagios users of all backgrounds. Everyone from a home lab to an enterprise will be able to get useful information and insights.

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Nagios Website Check

Nagios XI Free,Guide for the Windows Sysadmin

Getting Started with Nagios XI Free is Extremely Easy!

Please Note: This guide is intended for testing and evaluation only.

At MCS, we strongly feel that Nagios XI is the best IT monitoring software available and has been for quite a long time. XI is the more polished, easy to use product over the community Nagios Core software. We have seen some resistance from enterprises that are mostly Microsoft Windows shops. There is no Windows version of Nagios XI available so sysadmins have to use Linux. For some, this may seem daunting. Getting started with Nagios XI Free is actually one of the simplest Linux tasks out there. Starting from nothing, you can start monitoring in only a few steps. This guide is for the Linux and Nagios newbie so we will cover everything.

Nagios XI used to only be supported on RHEL and CentOS but is now fully supported on Oracle Linux, Debian, and Ubuntu. Right now, we like CentOS 7 Minimal as it is stable, completely open source, and tried and true for running Nagios XI.

Starting Out

  1. Download CentOS 7 Minimal (no GUI needed)
  2. Install CentOS 7. Since I am talking about Microsoft shops in this article, I will use Hyper-V. Use a Gen1 VM any don’t use dynamic memory. If you are using VMware you can get the OS+Nagios XI ready to go in an OVA. We have even run Nagios XI stably on AWS on a t2.micro instance with a few dozen checks running.
  3. Nagios has been optimized very well over the years. You only need 1 CPU, 1GB RAM, and 8GB Storage. Of course, the more resources you assign the better!
  4. After install, login as root.
  5. Now this is the really slick part. As long as your new CentOS 7 Server has internet access, you only need to run a single command to download and fully install Nagios XI.
curl | sh

The amazing engineers from Nagios keep this script up to date for you. Using this command will always get you the latest stable release of Nagios XI fresh from the factory! Grab a cup of coffee and watch a beautiful waterfall of text scroll down your screen.

Take note of the URL to access Nagios XI:

Nagios XI Installation Complete! 
You can access the Nagios XI web interface by visiting: http://<server_address>/nagiosxi

Once the install script is done, you now have a Nagios XI server of your very own. Just for best practices, you should now update your OS and software. Type:

yum update -y

Several items will update and you should reboot in case one of those updates was for the kernel.

In a browser, visit http://<server_address>/nagiosxi

If you missed the server address you can always run:

ip addr show

Now, set your nagiosadmin password and login via the web. By default, you will be using a 60 day trial of the Unlimited Enterprise Edition. If you plan to purchase Nagios, MCS can get you a key to extend your trial a little longer. If you want to use Nagios XI free, you don’t need any license at all. Just go to Admin > License Information and select free mode. This will let you monitor up to 7 different hosts with unlimited services.

Adding Hosts to Monitor

Nagios XI will monitor itself (localhost) by default. Adding common checks is easy though. Let’s say we want to keep an eye on our website.

  • Go to Configure > Configuration Wizards
  • Search for Website
  • Enter your url
  • Optionally customize your settings for your checks

In about one minute you are monitoring several critical metrics for a website. It is about as easy to monitor Windows Servers, Linux, networking gear, and just about anything with an IP address. It can actually be really fun and rewarding to finally get a real-time view into what is working and what is not.

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Nagios Free

3 Options for Using Nagios Free of Charge

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, 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 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.

Download Nagios Core

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.

Download Nagios XI

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.

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