A single data disk failure rapid reconstruction method with three-disk failure erasure code

Abstract

The invention discloses a quick single-disk failure recovery method for triple-erasure-correcting codes. The method includes: dividing each stripe unit of each stripe into p-1 sub-blocks during recovery of single stripes; acquiring a total number R<idea1> of the sub-blocks, used for recovering a failed disk, in each stripe; in an array of p+2 disks, initializing a feasible solution value for failure of the failed disk I into 3<p-1>; initializing a counter j=0; converting j into a recovered sequence which is ternary and which shares p-1 elements by means of the division algorithm; calculating a sum of bits with 0, 1 and 2 values in the recovered sequence of p-1 bits; comparing the three numbers pairwise; judging whether or not absolutes of differences are all smaller than or equal to 1; if yes, starting an effectiveness test function and judging whether or not test blocks, represented with the recovered sequence, are able to recover all data blocks in the failed disk i. The letter p is a prime number, with p+2 being equal to the number of disks in an RAID (redundant array of independent disks), and R<idea1>=R<low>+w%. The quick single-disk failure recovery method for triple-erasure-correcting codes has the advantages that disk recovery process can be quickened and system reliability is improved.

Description

technical field [0001] The invention belongs to the field of computer storage systems, and more specifically relates to a single-data-disk-failure rapid reconstruction method with three-disk failure erasure codes. Background technique [0002] Modern storage systems use redundant information such as error correction codes to ensure data availability and improve system reliability. The storage system can be a disk array composed of multiple disks, or a super-large-scale cloud storage system, such as Windows Azure Storage (WAS for short) developed by Microsoft, which supports various applications such as social network search . For a long time, researchers have spent a lot of time and energy studying various RAID6 encodings, including RDP encoding, EVENODD encoding and so on. [0003] figure 1 It represents a three-disk error-tolerant storage system composed of disk arrays. Here, each node is a disk, and the space of all disks is divided into blocks (also called stripe unit...

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Problems solved by technology

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to provide a rapid reconstruction method based on the three-disk failure erasure code in the case of a single data disk failure, aiming to solve the slow reconstruction speed when the existing reconstruction method faces a single disk failure , The problem of repeated reading of data, and by giving the ideal value of the amount of data read, using this as the optimal solution, and then using the heuristic search algorithm to search for the reconstruction sequence corresponding to the optimal solution, to speed up the disk reconstruction process, Improve system reliability

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