The original topic about doing a correct update as been closed.
I followed these instructions and coded this at openhab-qnap-qpkg:
While working with @chris on the ZWave binding. I noticed often problems after an update/upgrade.
There are always the same symptoms. Things are messing around and when starting OH2 in console mode and listing the log levels, after an update, no entry except of the default appears.
Reinstalling OH2 fixes the problem of course, but takes many hours compared to an simple update.
So the question is: Is this find of updating OH2 still valid, or is there a new way to do this? Maybe an additional directory I have to clean up?