@pdonias perfect thanks for the explanation - it works just like you said!
another question regarding the ACLs:
Can i give a specific User the right to create / schedule backups? Or is that only a admin privilege?
I had the same problem as @csi-laser - it was related due to no default storage SR in the cluster. I have a two node cluster with only local storage - no shared storage configured.
I added the SR UUID to the xe import command in the script an then the deploy worked!