The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 10, 2001
Filed:
May. 13, 1999
Alan R. Permut, Louisville, CO (US);
John Timothy O'Brien, Louisville, CO (US);
Keith Allen Radebaugh, Denver, CO (US);
Hendrikus Everhardus Vandenbergh, Lafayette, CO (US);
Storage Technology Corporation, Louisville, CO (US);
Abstract
A method for detecting and remembering multiple sequential access patterns made from a host to a memory system having one or more logical storage devices. Once a sequential access pattern is detected, one or more tracks are requested to be prestaged ahead of the current access request. The number of tracks requested to be prestaged ahead may be responsive to the amount of storage available in the cache memory. One list is provided for each logical storage device. Each list has multiple entries and is logically divided into two parts. A sequential part contains entries for access streams which the system has determined are sequential and for which the system may have prestaged one or more tracks into cache. A candidate part contains information about recent host accesses which have not as yet been determined to be sequential. The entries within each of the two parts of the list are logically ordered in a most-recently-used fashion. The division between the two parts of the list is allowed to change so that although the total number of entries may be held constant, the proportion of the entire list allocated to each of the two parts can be varied. Inactive entries in the list are invalidated over time.