I created a test that reports back some file sizes from a Windows server. The files don't change much, so I set the test to run every 15 minutes.

My rrd file has all NaN, even though I confirmed the data is reported using the lastupdate command in rrdtool.

I understand that this is because the default step/heartbeat are configured for a 5 minute window of checks, and my 15 minute checkins fall outside of this range, and therefore aren't added to the file.

These are my assumptions thus far, and if they are wrong, please correct me.

So what I did was use rrdtool tune command to change the heartbeat of my 5 data types to 1000 seconds. Which should allow my 15 minute updates to get logged correctly. Not sure if that has worked yet, hasn't been 15 minutes. But I wanted to ask about the rrddefinitions.cfg file.

I understand that I can change the step/heartbeat settings on RRD file creation using this file. But I can't understand part of the config. Here is the contents of that file: # 576 datapoints w/ 5 minute interval = 48 hours @ 5 min avg. RRA:AVERAGE:0.5:1:576 # 576 datapoints w/ 6*5 minute averaged = 12 days @ 30 min avg. RRA:AVERAGE:0.5:6:576 # 576 datapoints w/ 24*5 minute averaged = 48 days @ 2 hour avg. RRA:AVERAGE:0.5:24:576 # 576 datapoints w/ 288*5 minute averaged = 576 days @ 1 day avg. RRA:AVERAGE:0.5:288:576

I won't say I understand it all, but this is what I have deduced so far:

• RRA:AVERAGE: - needs to be there.
• 0.5: - Don't know what this is for. I assume it have something to do with the span of the step/heartbeat.
• 1: or 6: or 24: etc... - The number of datapoints collected per graph interval.
• 576 - The total datapoints saved.

Can anyone provide some insight into this file?

Thanks, Thomas