[CentOS] Nagios, getting started

[Mihamina Rakotomandimby]

On 06/22/2015 01:04 PM, Rob Kampen wrote:
> Hi List,
> I have noted a number of times, various comments on this list about 
> Nagios, hence my questions.
>
> just been employed by an ISP and they want to upgrade their fairly 
> extensive nagios monitoring.

Just for information, Nagios has been forked by some, for several reasons.
https://www.icinga.org/
http://shinken-monitoring.org/

I recommend you check the history in order to have the background.

> They are mostly an ubuntu lts shop, so 1st question
> What advantages does the RH/CentOS world have (if any?) over the 
> ubuntu LTS world?

There is a famous quote: "If ain't broke, dont fix it" 
https://en.wiktionary.org/wiki/if_it_ain't_broke,_don't_fix_it
If you have documentation, plugins, configuration all working with some 
flavor of a distribution, ease your work.

> They are talking about running the server on a vm, as I have no 
> experience with this tool, is that appropriate? or does it really need 
> some hardware resources to function properly?
> If a vm is okay, what kind of RAM does it need?

We run our monitoring tools (Nagios, Collectd, Munin,...) all on VMs.
It is ideologically OK to run this kind of service on a VM.

About ressources, VM are extensible: begin with small ressources, extend 
when needed.

> I see epel has nagios 3.5.1 with a date of 2013 for CentOS7 along with 
> plugins, is this the version folk use? - as the latest from nagios is 
> 4.0.8
>
> I am under orders to use packages and not compile, a viewpoint I endorse.
> Are there other repos folk use?
>

Packaging has advantages and drawbacks.
On the other hand, packages are built from compiling sources.
Some repos can be trusted for their packages quality, but some others 
might be personnal repos that might work only for the packager use case.
Some repos are listed on the CentOS website: 
http://wiki.centos.org/AdditionalResources/Repositories
Using a 3rd party repo requires some investigation.