Abstract: An improved read ahead strategy that improves the performance of a disk array subsystem. The disk controller keeps track of the last n reads to the array. If a new read request is received that is adjacent to any of the last n reads, the controller performs a look ahead read because a sequential read may be in progress. The parameter n is preferably set comparable to or greater than the number of maximum independent activites being performed by the computer system. Therefore, in a multithread system, the controller performs a readahead if any one thread is doing a sequential read.
Type:
Grant
Filed:
December 17, 1991
Date of Patent:
January 9, 1996
Assignee:
Dell USA, L.P.
Inventors:
Craig S. Jones, Kenneth L. Jeffries, Terry J. Parks