I am looking for a reference to what the prefixes shown in the munin graphs mean, e.g.,
k, etc. I can guess several, but it would be helpful to have a complete list.
Complete list, courtesy of Wikipedia.
It really depends on the individual plugin that generated the graph, and the graph should include information about whether the unit is request per second, response time, number of reads/writes (io) or whatever it might be.
The four types of datasources are COUNTER, ABSOLUTE, DERIVE and GAUGE. With a default to GAUGE.