What tool do you use to monitor your servers?
I'd like to get a good overview of the various monitoring tools. I'm looking for something modern, fresh and lightweight that gives me insight in the trends of CPU usage, memory usage, disk usage, network traffic, etc.. and optionally can give alerts about it.
The server already has the HP-SNMP-Agents installed, so those could be used for information retrieval.
I currently run one server, and plan to add a few more.