| 摘要 |
PROBLEM TO BE SOLVED: To provide a backup mechanism which always efficiently stores backup data by well-knit data compression processing, even if backup data included cause increase of data volume from the data size of before the compression due to the compression, when storing the backup data in an external storage device. SOLUTION: In a magnetic tape device 20, a CPU 21 stores original data received from a host computer 10 and the data compressed by a data compression mechanism 24 to a memory 22, and compares these data sizes. If the size of the data compressed is smaller than the size of the original data, the compressed data are stored in a magnetic tape 25 as backup data, and if the size of the compressed data is equal to or larger than the size of the original data, the original data are stored in the magnetic tape 25 as backup data. |
