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:
Apr. 07, 1998
Filed:
Aug. 15, 1995
Albert Stephen Hilditch, Wokingham, GB;
Ian Gregory Colloff, Ascot, GB;
International Computers Limited, London, GB;
Abstract
A RAID system includes an array of disk units, with data mapped on to the disks as a series of stripes, each containing data and parity chunks. The data chunks of each stripe are located on radially more outer parts of the disks and the parity chunks of each stripe are located on radially more inner parts of the disks. As a result, the amount of head movement for read operations is reduced, which improves the read performance. Successive chunks within each stripe are physically located at successively more radially inward positions on successive disks, so that each stripe has a helical configuration. Mirroring can be considered as a special case in which the number of data chunks is equal to the number of parity chunks, and the parity consists of a simple replication of the data. In this case, data is written to the outermost half of a first disk and to the innermost half of a second disk, and is read from the first disk.