| 摘要 |
PURPOSE:To successively execute access to a file existing on a secondary storage medium, by holding a block number and an in-block relative position address in a file address storage area, and holding a data block in a buffer area. CONSTITUTION:In a sequential access request sent to secondary storage mediums 31, 32 from computers 11, 12, a control means 6 of a control unit 2 obtains an address to be written, from a file address storage area 7 and sends it to a data buffer control means 8. The means 8 searches the inside of a data buffer area 9, and when a request block does not exist, a transfer of a block unit is executed to the area 9 through an input/output means 10. Also, with respect to an updated block, a flag is set, and sent to the means 6. Thereafter, a completion of the processing is informed to the computers 11, 12 through a processing request answer means 5. On the other hand, in case of sequential read request, the processing is executed by referring to an operation of a sequential write request, a read processing, and a sequential read use address of the storage area 7. |
