Abstract: A method for creating a duplicate copy of a tape in which a first tape having a first data set name and a second tape having a second data set name are allocated. Data is written to the first and second tapes so that block for block, the data is located at the same position on each of the tapes. After data is written to one of the tapes, a check is made to verify that the data was written correctly. If an error is detected in writing the second tape, an error flag is set that indicates a copy of the first tape needs to be made. At various stages of the process, checks are made to determine if error flag is on. If the error flag is detected, writing the second tape is suspended.