Method and system for accessing data from a multi-head data processing system utilizing a transducer head switching table

摘要

A method and system for enhancing the efficiency of data accessing within a storage subsystem which is coupled to a host system via a storage subsystem controller and a data channel. The storage subsystem controller preferably includes a tracked cyclic storage device which has multiple disks which are rotatable about a single spindle. Recording tracks within each disk are then accessed utilizing multiple switchable transducer heads. A signal transmitted from the host system is utilized to define a sequence in which a group of recording tracks are to be accessed. That signal is then utilized to create a transducer head switching table within the storage subsystem controller which lists each recording track to be accessed and an associated control parameter for selecting a particular transducer head to be utilized to access a subsequent recording track. Each time the end of an accessed recording track is encountered, the transducer head switching table is accessed and the control parameter associated with that track is accessed and coupled to the tracked cyclic storage device transducer head switch in order to select a subsequent recording track for access. In this manner, a plurality of tracks may be accessed in any desired order. A pointer is established into the transducer head switching table at the listing of an initially accessed recording track and access may be terminated when that pointer is encountered.