So far, I could solve all my monitoring needs (like CPU and memory usage, network traffic, and disk activity) with ksysguard. It was what came preinstalled with KDE, it's easy enough to figure out, it is easy to adapt the display to whatever you're looking for, and with a bit of google & error I was able to set up ksysguardd on remote systems to do over-the-network monitoring, too. Being able to save log data to file was also useful.
Now, I would like to log such performance data on the remote server, i.e. without having a ksysguard instance running on a "monitor system" locally. I know that this should actually be easier than transferring the data over the network and displaying it in graphs and bars, but I honestly admit I am clueless.
Googling gave me links to several enterprise-level, everything-and-the-kitchen-sink solutions, but it seemed none of them would be quite as easy to set up and configure as ksysguard was (especially not without root access on the to-be-logged system), and I am not sure I am up to the task, and certainly not willing to invest more than 1-2 hours into the subject.
Can you people give me suggestions on simple performance logging solutions for Linux?
Edit: I should have mentioned, one of the core requirements is that the logging must be able to run without root access.
There are a number of possibilities. However, like you mentioned, they are all rather cumbersome to set up. Zabbix, Munin, Nagios and the like seem quite popular.
Maybe sysstat combined with kSar for graphs?