Patent ID: 6338115
Filing Date: 2002-01-08
Classification: G06F

Abstract:
A method of caching data for a direct access storage device having a plurality of addressable locations, comprising the steps of:storing, in a cache memory, copies of equally sized bands of data retrieved from said direct access storage device, each said band comprising a predetermined number of contiguous addressable locations on said direct access storage device spanning a plurality of sectors on said direct access storage device, responding to a request for access to a storage device location for which a copy is stored in the cache memory, by accessing the copy stored in the cache memory, and maintaining statistics on the type of access made and band in which the access is made, and responding to a request for access to a storage device location for which a copy is not stored in the cache memory, by retrieving data for a band of said predetermined number of contiguous addressable locations on said direct access storage device, the band including said desired storage device location and contiguous addressable locations adjacent thereto, storing said retrieved data for said retrieved band into said cache memory, and responding to the request for access to the desired storage device location by delivering a portion of the data that was retrieved from the storage device and stored in the cache memory.