| 摘要 |
<p>A drawback of reading new data due to the fact that old data cannot be completely overwritten by the new data is prevented from occurring. In a controller (16) of tape drive, a command processing unit (41) accepts a demand for writing new data. An offset decision unit (44) decides whether or not the old data has the portion which is not overwritten by the new data. If the answer is YES, a head position management unit (45) offsets a writing head to the portion, and a channel input/output unit (43) reads out the pattern data for invalidating the old data from a pattern storage unit (47) and outputs the read data to the writing head so that the old data is overwritten by the pattern data. A tape travel management unit (46) then returns the tape, and the head position management unit (45) returns the writing head so that the old data is overwritten by the new data.</p> |
