| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to detect errors and to appropriately restore them even when there occur condition in which plural blocks having the same logical addresses simultaneously coexist (a logical address error) or condition in which a block indicated by a link address does not exist (a link address error) caused by forcedly removing an external storage device. SOLUTION: In storing data in an external storage device in which a storage area is divided into plural blocks, the data are stored by allocating logical addresses to blocks and at the same time identification numbers for indicating new/old data concerned in the blocks in which the data are stored. Then, in reading the data out of the external storage device, when there exist plural blocks having the same logical address, the new/old of the data stored in those blocks are discriminated on the basis of the identification numbers, new data are recognized as invalid data and old ones valid data. |
