Data not being presented in HABmin from RRD4J

I’m building out my first OpenHab system using OpenHabian on a RPi 3b. I installed HABmin and RR4D through PaperUI, and added and rr4j.persist file like this:

Strategies {
        everyMinute : "0 * * * * ?"

        default = everyChange

Items {
        ToChart*   : strategy = everyUpdate, everyMinute

I have a group in my items file with called ToChart containing several Number and Switch items. I have made no manual changes to rr4j.config. The installation through the UI has left it like this:"true""org.openhab.rrd4j"

I can see that rrd files were immediately created for every item which is bound to a channel and every group to which they belong. The modified date does not change on any of these files unless I reboot. The log shows that the values of the items do change. Apart from loading the .persist file, I never see any log entries relating to RRD4j.

A call to the REST API at /rest/persistence/items?serviceId=rrd4j always returns an empty array. Is that why HABmin do not allow me to create charts of my data?

Have a missed a step somewhere? Is there something missing from the automatic installation?

Edit: In my next post I found that there is actually data there, so it’s more of a mystery why HABmin charting does not present it.

The files should be named rrd4j.persist (in the persistence folder) and rrd4j.cfg (in the services folder).
My rrd4j.cfg does not hold anything like your entries, in which directory do you have that one?

The REST call you used Returns empty for as well. What are you getting for a call /rest/persistence/items/YourItemName?serviceID=rrd4j

Thanks for your reply. My persist file is at srv/openhab2-conf/persistence/rrd4j.persist. To confirm, the entries in the rrd4j.cfg are defaults from my fresh installation. I read elsewhere that customisation of that file should not be necessary, but maybe that information is out-of-date.

The REST call you used Returns empty for as well. What are you getting for a call /rest/persistence/items/YourItemName?serviceID=rrd4j

Thanks for the suggestion, it seems that data is being stored after all. A sample from result of /rest/persistence/items/UF_Bedroom1_Temperature?serviceID=rrd4j:


So it seems the real question is why HABmin is not noticing this data and presenting it to be charted. I’ll add a HABmin tag to the thread.

I was expecting that result! A .cfg with only Defaults does work!
Since I do not use HABmin, I can’t help on that topic.