Moving documents from one bucket to another


I am trying to move documents from one bucket to another (on a running cluster). I have found several options on how to copy the files(using N1QL, backup and restore, cbtransfer), but my goal is to copy and delete the files from the original source so that no data is lost in the moving process. Currently all the processes I’ve looked at seem to require copying and deleting in two “transactions” which means if the copying process has finished the data could be overwritten and when I start the deleting process I would delete the new data. Is there a better way to do this, perhaps a tool option I have not yet discovered?