Oh 4.1.0.rc1

Setup, Configuration and Use Migration
1

With version 3.4.1 I had sometimes that rrd4j was stopping for a couple off hours. Mapdb was reliable. Now with the new version rrdj4 is stopping but not starting again and because after a restart of the system my previous values are wrong I assume that mapdb is also not working.
I tried to stop and start the services and that seems to work for mapdb but when I stop rrdj4 I get the following error. I saw many remarks about persistence but could find if this was fixed.
_Is there a place to look for the status?
_Is there a way to check if mapdb is working. I like to restart but with the last values.

Error stopping bundle305: Unable to acquire the state change lock for the module: osgi.identity; type="osgi.bundle"; version:Version="4.1.0.RC1"; osgi.identity="org.openhab.persistence.rrd4j" [id=305] STOPPED [STOPPED]
2

Any reason why you ate using RC1 and not the release.
Apart from that, I would recommend to use mapDB persistence for restoreOnStartup, ad RRD4J only stores numerical values.
Furthermore I can confirm both are working reliable over here.
You can enable debug/trace log for both to see any issues in the logs.