Patent ID: 6772283
Filing Date: 2004-08-03
Classification: G06F

Abstract:
A disk control device coupled to a first host device, a second host device, and a disk unit, said disk control device comprising:a first channel adapter coupled between the first host device and the disk unit, said first channel adapter receiving a first access command in a first format from the first host device and returning processing results to the first host device; a second channel adapter coupled between the second host device and the disk unit, said second channel adapter receiving a second access command in a second format different than the first format from the second host device and returning processing results to the second host device, said second channel adapter comprising an address conversion unit converting a position address in the second format received from the second host device into a position address in the first format; a device adapter coupled to the disk unit and executing an access command from one of the first host device and the second host device to the disk unit in blocks in the second format; a cache memory coupled to the device adapter, to the first channel adapter, and to the second channel adapter, said cache memory developing and storing track data as cache blocks in a format that divides a single block of the first format into several blocks of the second format; a cache function engine coupled to the cache memory and controlling the cache memory; and a resources manager coupled to the cache function engine, to the cache memory, to the first channel adapter, and to the second channel adapter, said resources manager comprising: a first controller calculating a block number in the second format of the disk corresponding to the position address in the first format received from the first host device, reading from the disk unit a block in the first format including the block in the second format indicated by said block number in the second format, developing and storing the block in the cache memory, and searching the cache memory for a record specified by the first host device, and a second controller calculating a block number in the second format of the disk corresponding to the position address in the first format received from the second host device, reading from the disk unit a block in the first format containing the block in the second format indicated by the block number in the second format, developing and storing the block in the cache memory, and searching the cache memory for a record specified by the second host device.