Is it possible to copy the NDS Tree from one server to another. The old server was a standalone and the new one should be the same Normally it is not possible to have two standalone servers interacting. So how can one copy the tree ?

If you add the second server into the tree then it will be automatically assigned a Read-Write replica of the NDS (since it is only the second to be installed). The master copy will still be held on the original server, but then if you remove the first server you can update the read-write replica on the second to a master replica. Alternatively, set up the second one in a new tree (with just the Root, nothing else). Then merge the 2 trees, with the new server as the target. This would make the new server have the master replica, and the old one would just have a read-write replica.