Note 1: Due to the setup of rrd4j databases a wrong value saved in archive 1 will also affect corresponding values in further archives. The way the other archives are effected depends on the consolidation function used. One should consider to check/update all archives when trying to remove a false value.
Note 2: In order not to work on the database in question while it is written too, openHAB should be stopped.
The file “rrd4j-2.1.1.jar” which is used by openHAB is needed ( on my openhabian installation to be found in folder “/var/lib/openhab2/cache/org.eclipse.osgi/222/.cp/lib”).
If openHAB is running on a headless raspberry, one should copy the .jar and the the .rrd file to another system that has Java installed.
Having both (the .jar and the .rrd) in the same directory the rrdInspector is started on the console with (on a windows system the console has to be started as Adminstrator!):
java -cp rrd4j-2.1.1.jar org.rrd4j.inspector.RrdInspector
Select your .rrd file and open the Archive for editing.
Change all false values by selecting the value under the “Archive Data” tab. Finding the values is easy since DateTime is given in a readable format.
Close the inspector.
Copy the changed .rrd back to your openHAB system and restart openHAB.
[Edit:] The actually used rrd4j*.jar (atm version 3.1.1) doesn’t include the RrdInspector anymore, trying to start it as posted above would give this message: Fehler: Hauptklasse org.rrd4j.inspector.RrdInspector konnte nicht gefunden oder geladen werden (in english: Error: the main class org.rrd4j.inspector.RrdInspector could not be found or loaded).
Solution: Use Google to find a rrd4j*.jar including the rrdInspector (I used this)