Some days ago i've installed a nagios' instance on my server, looking if nagios was the right application for my needs.
Sincelery i think Nagios is a powerful and scalable monitoring application, but i'm afraid of nagios can monitoring only one server for each instance, so for monitor two different web server on two different ip i need to install two time nagios on each web server.
I'm searching for an application who can monitor more server in a single instance.
Ex: server nagios on 12.34.45.57 pc. production server number 1 on 45.45.65.76 pc production server number 2 on 65.34.35.76 pc
Does nagios provide situation like the one above? If not, someone knows some sw who provide me to monitor more production server?
Thanks
Nagios uses TCP communication to talk with NRPE clients installed on all servers you want to monitor. So, while all servers don't require the entire Nagios Monitoring Solution, they do require a small client app installed.
SEE:
http://nagios.sourceforge.net/docs/3_0/addons.html
You didn't mention, what kind of "monitoring" you want to get. If you just want to monitor "public" services, accessable via the network, Jonathan Ross's answer is correct. If you want to monitor CPU load, disk free space, processes count, etc., you will need to install "nrpe", the nagios agent. To provide such type of monitoring, any monitoring system will need its own agent.
If I understand correctly, yes, it does.
You just set up a host for each IP you want to check. Then what services on each IP.
The answer is "yes, but..." If everything you want to monitor can be reached from the server you installed nagios on (for instance, webservers, mailservers, etc) then nagios can monitor it all from one place.
The "but..." is for things that you can't check remotely (free disk space, computer load), you're going to have to do a little work, but you still don't have to install the entire nagios monitor onto each server. One way to do this would be to install an SNMP server that nagios can query for the information. Another method is to install Nagios's NRPE server, which allows Nagios to run specifically-configured commands (eg check_disk) on the remote server.