Nagios Support Forum

Have installed nagiosxi.

Everything working for same server.

Now want to monitor same services on another linux server that has also nagios installed.

Found http://www.tecmint.com/how-to-add-linux ... ng-server/

not sure if above url is correct since it mentions installing additional software on current server.

Our official document for using NRPE to monitor another linux server can be found here - https://assets.nagios.com/downloads/nag ... g_NRPE.pdf

You may not need to install additional software though, it depends on the services you're looking to monitor. What exactly are you looking to check for on the remote server?

Also just to clarify, you do not need to install Nagios on every server you wish to monitor. You only need one Nagios server, then an agent like NRPE is installed on the remote machine to monitor the internal metrics.

it is a 3-node cluster and i'll install nagios server on 1 server (called A say) and install the nrpe agent on the other 2 servers (called Y, Z).
if Y, Z goes down, then A will notify me meaning will send me email.
if A goes down, then how will I get notified?
So shouldn't i install the server also on servers Y and Z.

On servers Y, Z and A, I want to monitor: cpu, memory, services like nginx, etc.

You're going to want to take precautions to make sure that your XI server is not going down. One solution I have seen is have a Raspberry Pi monitor your VMWare host, so if that dies you'll still get an alert. It's a little bit redundant, but if the piecve of hardware XI is running on goes down at least you'll have something alert you.

Not sure how the Pi would do the monitoring, but it sounds interesting.
I seem to recall one possibility is the have a Nagios server w/ all the monitored hosts defined on it and another w/ only the 1st Nagios server defined.

Every Nagios XI License key is valid for 3 installs, each with their own specific purpose.

• Production
  Test/Lab Environment
  Backup

Utilize your DR instance to monitor the production instance. This way, if the production instance goes down, you’ll receive alerts about it.

Nagios XI comes with a “Nagios XI Server” monitoring wizard to ensure everything is A-OK.

https://support.nagios.com/kb/article.php?id=501

Edit: I confirmed w/ sales that just one of the primary/backup pair is licensed to monitor at any given time.

My understanding of the backup/failover/DP portion of the license is that it is not to be used for active monitoring until the primary fails. Thus, the backup would not help to monitor the primary, if we adhere to the letter of the license.

Interestingly, the test part of the license is also not to be used for monitoring, only testing/development. Thus the 3 phase license is more restrictive than it appears.

This leads us back to the stand alone Nagios monitoring only the primary Nagios, or some other solution...

gormank wrote:Not sure how the Pi would do the monitoring, but it sounds interesting.
I seem to recall one possibility is the have a Nagios server w/ all the monitored hosts defined on it and another w/ only the 1st Nagios server defined.

I should have specified, I'd run Core on the Pi.

Gotcha, thanks!
Theoretically, w/ a single (or few) monitored host, XI has a no cost license.