Influx dB + grafana no values


Unfortunately, no more values are displayed.
What could be the reason for this?
How can I check whether the values are still being saved?

during boot i got this erorr:

An error occurred while calling method 'QueryablePersistenceService.query()' on 'org.openhab.persistence.rrd4j.internal.RRD4jPersistenceService@15cbce4': Unknown datasource name: state

Grafana uses influxdb.
RRD4J is a different type of persistence DB.

You can use the influxdb client and run your own query but I doubt that it will show different values.
On a standard installation the data would be stored in directory /var/lib/influxdb in directories data, meta.
You could check if the timestamp changes over time which I would expect to see only in cases when new data is added.

is there a way to shot the change date in the console?
It seems to me that nothing is written to the database.

Have a look at Using influx - InfluxDB command line interface | InfluxDB OSS v1 Documentation