Worldwide Performance/Usage Monitoring Software?

Wee asks: "I've got a need to monitor a bunch of Sun Solaris boxes worldwide for various load statistics. Things I need to see are disk I/O, CPU usage, RAM usage, IP traffic, etc. I need reports by the hour, day, week, month and year (as near real-time as possible). The reports have to customizable. I don't have a GUI running, so these stats need to be compiled from the console, and remotely. I can't figure out how to log system/network/load/usage statistics without loading the server in doing so. All the packages I've found so far are either limited or not appropriate in some way. I'd really like to hear how to monitor something without affecting the monitored thing. Since I need pretty precise numbers this is kinda important. I'm sure there's something somewhere that does what I need, but I can't seem to find it. If I have to use multiple tools and collate data then I will, but this wouldn't be ideal. "