Restore Persistance after Migration (MapDB)

How can i restore my persistance file from OH2 to OH3.I tried copying over my 3 files (storage.mapdb, storage.mapdb.p, storage.mapdb.t) from /var/lib/openhab2/persistence/mapdb to /var/lib/openhab/persistence/mapdb but after i start OH3 it wipes the files clean and starts over.

You don’t. Mapdb just stores the last state so it’s useless to keep across version changes anyway.

I restore all my values at startup from mapdb.

It just means a lot of static values (dummy switches/dimmers that store specific values for Light Brigtness based on time of day/etc) are all lost.

Sure we all do. Once you migrated mapdb will work again.
Then again, proper programming includes proper initialization of all items anyway.

I migrated and when i started OH3 no mapdb restoreOnStartup items inherited its previous values.
I tried stopping OH3 and copying the mapdb files from /var/lib/openhab2/persistence/mapdb to the mapdb folder for OH3, but upon a start those files got written over and no values were restorted from the OH2 previous state instance.

You already wrote that. You cannot carry them across version. Reinitialize your items.