Regenerating Charts after rebuilding openhabian SD Card (external MariaDB)

Hi all,
I’m running openhabian 3.0.1 on a Raspberry PI 3 with a remote MariaDB instance. The SD card no longer works, so I had to replace it. Thankfully, I could restore the SD card image from an Amanda backup and generally speaking everything is working again as before. Everything that is, except for the historical graph data (Page of type Chart) up until the crash. Any hints on how I can get the old data displaying again?
Thanks heaps,

New data after restore is stored in the same remote MariaDB and is being shown in charts ?
Have you checked by using SQL commands if data from before restoring and after restoring is available in the same column ? This is just to make sure that you access the same instance ( a new one was not created; old data was not deleted for whatever reason ).

Yep, the new data is definitely being created in the same places as the old data. Could it be that the chart data is coming out of rrd4j or somewhere else on the Raspberry PI?

That’s installed, configured, and used for charts by default. If you want charts to use something else, you have to tell openHAB (default persistence)

1 Like

Did you properly restore the old persistence data from backup ?
It’s a dedicated file system so has to be restored separately.

1 Like

This I’m not really sure about. The MariaDB is on a Synology NAS and wasn’t affected by the SD card crash. I can confirm that the old data and new data are in the same tables. The default persistence is (and was) set to JDBC.

One thing I noticed is that some values which don’t change very often (Target Hot Water Temperature for the water heater) didn’t start displaying on the chart until I changed the value. This seems to confirm that the chart data is not being read directly out of the MariaDB, but out of some cache on the SD card or in the working memory of the PI, which wasn’t regenerated when I restored and old version of the SD card.

New information: when the Rapsberry PI is restarted, none of the data from before the restart is shown, so it not only a question of before the SD card rebuild. As this changes the context of this whole question, I’ve started a new thread: Regenerating Charts after openhabian restart