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Method for implementing fault-tolerant redundant disk subsystems

IP.com Disclosure Number: IPCOM000109303D
Publication Date: 2005-Mar-23
Document File: 2 page(s) / 31K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for implementing fault-tolerant redundant disk subsystems. Benefits include improved functionality, improved availability, and improve reliability.

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Method for implementing fault-tolerant redundant disk subsystems

Disclosed is a method for implementing fault-tolerant redundant disk subsystems. Benefits include improved functionality, improved availability, and improve reliability.

Background

      Redundant disk arrays can be used to build highly available and reliable disk subsystems. Conventionally, the result from an exclusive-OR operation performed on data from some number of disks is maintained on a redundant disk. In the event of a disk failure, the data on the failed disk is reconstructed by performing an exclusive-OR operation on the surviving disks. The result is written to a spare disk.

      Redundant disk architectures conventionally provide recovery from disk failures. However, recovery may not be possible without powering down the system to replace the failed unit.

More expensive fault-tolerant systems attempt to eliminate single points of failure to improve system availability.

      Various serial interface technologies are replacing conventional parallel interfaces. Some implementations can recover from single and double disk failures and a single serial controller expander failure. However, if the input/output (I/O) processor fails, the system must be powered down. Some implementations avoid powering down due to failure by having two I/O processors.

              Conventionally, data integrity mechanisms do not protect against phantom writes, resulting in silent data corruption.

Description

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