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:
Mar. 12, 1996
Filed:
Oct. 14, 1994
David W Gordon, Boulder, CO (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A fault-tolerant storage device array using a solid-state storage unit for storage of redundancy information. The invention solves the redundancy bottleneck inherent in a RAID 4 architecture by replacing the electro-mechanical redundancy storage unit with a solid-state device (SSD). The present invention requires reading an old data block from a storage unit and an old redundancy data block from the SSD, then combining the old data block, a new data block, and the old redundancy data block to generate a new redundancy data block, and thereafter writing the new data block to a storage unit and the new redundancy data block to the SSD. However, reading the old redundancy data block from the SSD and writing the new redundancy data block to the SSD at electronic speeds takes a negligible amount of time compared to the Read and Write times of a typical rotating disk storage unit. While the storage unit on which a new data block will be stored is involved for the duration of each data modification operation, the involvement of the SSD in the operation ceases upon writing the new redundancy data block. Thereafter, the SSD is available for updating a redundancy data block for a next storage unit.