Nagios Support Forum

How much memory required by nagios Core to monitor 20+ server? (Each server around 30 service).

Please let me know what type of aws server is enough for nagios server to monitor nagios client with nrpe?

Honestly you could probably get away with whatever is recommended for just the OS install plus few MB. 20 hosts x 30 services = 600 checks (plus 20 for the hosts themselves). I wouldn't go below 2GB if you can help it, but I've seen Core run on 1GB with no problem. It all depends on what else is running and what sort of checks you have.