In one aspect of the present invention, an apparatus includes a head configured to write data to a tape, and a hardware controller coupled to the head. The controller is configured to cause the apparatus to copy a second data area on the tape as a third data area, the second data area corresponding to data in a first data area that has changed. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the third data area, and copy the first data area to the tape as a fourth data area separate from the third data area. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the fourth data area.