Hi guys, i have been searching over the docs a lot the last few day, hence i am very new to RRD and i've been trying to get something going. I am trying to migrate from an old software of mine, which uses RRD to a new software, which doesnt. So far i've figured out how to dump the rrd tables and what does rrd to when saving the values, however i've had issues getting the same values that get stored inside rrd. Here is a quick example i made, hope you can give me a hand.
I made a simple php file, which runs every 300 seconds and updates a RRD database. The cycle checks if the .rrd file exists and if it doest, then it creates it: Here is my create statement (the one my old software uses): rrdtool create test.rrd DS:cpu:DERIVE:800:0:112500 RRA:AVERAGE:0.5:1:600 And immediately after the file is created, the script runs an update statement: rrdtool update test.rrd N:5848 (the value above is an example). Now my script updates exactly every 300 seconds after it has started running, so i'm sure the timing is exactly 300 seconds apart. Now, here are the values i have tested with: (timestamp - value) 1363128441 - 5791 1363128741 - 6665 1363129041 - 7482 And here are the results rrd has stored (this is from a xml dump): <row><v> 2.9050692504e+00 </v></row> <row><v> 2.8128932327e+00 </v></row> Now as per my understanding, the first value should be the result from: (6665 - 5791)/300 = 2,913333333333333 ... which doesnt match the first value. The same issue applies to the second value and any other value i have tested. What am i doing wrong ? Thank you. -- View this message in context: http://rrd-mailinglists.937164.n2.nabble.com/rrdtool-getting-incorrect-values-after-update-tp7580838.html Sent from the RRDtool Users Mailinglist mailing list archive at Nabble.com. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
