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:
Oct. 22, 1996
Filed:
Oct. 11, 1994
Jeffrey J Dobbek, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A DASD array and method wherein spindles in the array are synchronized in speed of rotation and phase. The invention includes a plurality of spindles and at least one disk rotating around each spindle, wherein each disk comprises a plurality of tracks arranged into synchronization zones. The synchronization zones comprise a plurality of data sectors and an excess time period associated with each zone. The excess time period comprises raw and synchronization skew, wherein the skew is used to shift sector locations in response to excessive defects occurring in the synchronization zone on the disk. In this manner, the phase of the disks in the system are synchronized without consuming additional disk storage capacity. Each disk also contains skip profiles for controlling the distribution of unused sectors across the disks. The skip profiles are distributed to model the defect profile in the worst disk in the system. The skip profile and the skew are used in combination to shift sector locations back when defects are present.