Phantom duplex copy group apparatus for a disk drive array data storge subsystem

Patent 5239659 Issued on August 24, 1993. Estimated Expiration Date:

June 19, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventors

Assignee

Storage Technology Corporation

Application

No. 717820 filed on 06/19/1991

US Classes:

714/6, Redundant stored data accessed (e.g., duplicated data, error correction coded data, or other parity-type data)703/24, Of peripheral device714/7Reconfiguration (e.g., adding a replacement storage component)

Examiners

Primary: Harrell, Robert B.

Attorney, Agent or Firm

Duft, Graziano & Forest

International Classes

G06F 012/16
G06F 013/00
G06F 011/80

Abstract

This apparatus makes use of a disk drive array to store data records for an associated host processor. This disk drive array emulates the operation of a large form factor disk drive by using a plurality of interconnected small form factor disk drives. These small form factor disk drives are configured into redundancy groups, each of which contains n+m disk drives for storing data records and redundancy information thereon. The use of this configuration is significantly more reliable than a large form factor disk drive. However, in order to maintain compatibility with host processors that request the duplex copy group feature, the phantom duplex copy group apparatus of the present invention mimics the creation of a duplex copy group in this dynamically mapped data storage subsystem using a disk array and a phantom set of pointers that mimic the data storage devices on which the data records are stored.