Be aware of the following properties of |copydb|:
- |copydb| runs on the destination :program:`mongod` instance, i.e. the host receiving the copied data.
- |copydb| creates the target database if it does not exist.
- |copydb| requires enough free disk space on the host instance for the copied database. Use the :method:`db.stats()` operation to check the size of the database on the source :program:`mongod` instance.
- |copydb| and :dbcommand:`clone` do not produce point-in-time snapshots of the source database. Write traffic to the source or destination database during the copy process will result in divergent data sets.
- |copydb| does not lock the destination server during its operation, so the copy will occasionally yield to allow other operations to complete.