Mass storage array with efficient parity calculation

• US 5,191,584 A
• Filed: 02/20/1991
• Issued: 03/02/1993
• Est. Priority Date: 02/20/1991
• Status: Expired due to Term

• Current Assignee: Intel Network Systems, Inc. (Intel Corporation)
• Original Assignee: Micropolis Corp.
• Inventors: Anderson, Michael H.
• Primary Examiner(s): ATKINSON, CHARLES
• Application Number:
  US07/658,317
• Time in Patent Office: 741 Days
• Field of Search: 371/51.1, 371/49.1, 371/10.1, 365/200, 360/53, 395/575, 364/265.3, 364/266.3
• US Class Current: 714/6.24
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 2211/1054 Parity-fast hardware, i.e. dedicated fast hardware for RAID systems with parity
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence

Abstract

An efficient redundant array of mass storage devices includes a plurality of hard disk drives, a controller or processor associated with each hard disk drive for calculating partial parity data and parity data, a host computer and at least one bus for communications between the host computer and the plurality of hard disk drives. The controller of a drive calculates the partial parity, which is the Exclusive Or function of the old data and the new data which is to be stored into the drive. New data is written to the location in the disk drive from which the old data was obtained. The partial parity data is transferred to the controller of another drive which contains the old parity data for the location to which the new data was written, and that controller calculates the new parity which is the Exclusive Or of the partial parity and the old parity. The new parity is written to the location on that disk drive which formerly held the old parity.

Claims