Just upgraded from 3.3 to 3.4. this was a fresh 3.0 install (if i remember correctly)
The online docs state:
openHAB ships with the rrd4j persistence service installed by default, which persists every Item on every state change and at least once a minute. Additionally, it restores the last stored value at system startup. To change this behaviour see Persistence Configuration.
this isn’t true for me, I’m checking in the persistence folder and there is only the readme file.
Should it be there? is the documentation incorrect?
If you didn’t upgrade from 2.x at some point and you haven’t used /etc/openhab/services/addons.cfg to manage you installed add-ons than rrd4j will be installed by default.
No, there shouldn’t be an rrd4j.persist file in the /etc/openhab/persistence folder. OH never writes to that folder, only reads. When there isn’t an rrd4j.persist file the default strategy is used which is to persist everything on everyChange and every minuted with restoreOnStartup (see the rrd4j’s add-on docs for more details).
In MainUI, you can see which persistence add-ons you have installed in Settings → Persistence where you can select from among the installed persistence add-ons which one is the default.
Hmm… yes, that’s right. I meant the var/lib/openhab/persistence/rrd4j folder. There’s gotta be a lot of .rrd filed - for each item one file! So, if there’s no rrd-files, then rrd4j isn’t active
@BigCol you can easily test this with an item. open it in the UI and click on “analyze”. If you didn’t define some kind of persistence and there’s an history chart, everything is fine (number items should show a line graph, switch-items show 0 and 1)