RAID, data reading and writing and its rebuilding method

Abstract

The invention discloses an RAID model. The RAID model comprises an RAID core verification module and an RAID core scheduling module; the RAID core verification module adopts an Erasure code verification algorithm of RS code on the basis of a Vandermonde matrix, the Erasure code verification algorithm supports N data blocks to generate M verification data, and the RAID core scheduling module is used for conducting unified scheduling on all data reading and writing operations of the RAID model; the RAID core scheduling module selects N correct data blocks through a scheduling algorithm, and corresponding M verification data is calculated through the RAID core verification module; an RAID core I / O module is used for executing data reading and writing operations of the RAID; the RAID core scheduling module creates an object container containing all data. According to the RAID model, the RAID core scheduling module conducts unified scheduling on all the data reading and writing operations of the RAID, a user does not need to conduct caching for length adaptation, the verification number can be customized, no state exists for attitude to data, overall reconstruction is not needed, and the reading and writing efficiency is high.

Description

technical field [0001] The invention relates to the technical field of RAID storage modes, in particular to a RAID, data reading and writing and a reconstruction method thereof. Background technique [0002] With the revival of storage technology and the advent of the era of cloud computing, storage products have penetrated into every aspect of our lives. How to make data safer, more efficient in storage, and more convenient in application is something that needs to be faced in the development of storage products. The traditional RAID (Redundant Arrays of Independent Disks, disk array) 5 storage mode is to establish a horizontal space storage model by cutting the space of each disk horizontally, so that each disk can work together to improve storage efficiency, and use the XOR algorithm to save The data has N+1 redundant backup. [0003] The data segmentation method of RAID 5 is to divide all the disks horizontally and logically splicing the data blocks of the same length o...

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Problems solved by technology

[0003] The data segmentation method of RAID 5 is to divide all the disks horizontally and logically splicing the data blocks of the same length on each disk horizontally into a striped data structure. The length of the stripe cache (stripe buffer in memory) It is proportional to the number of disks, for example, Stripe_cache_size=4k*working_disks_nr*chunk_size; however, under normal circumstances, programs in user mode (especially in the field of surveillance video) are a kind of additional input, including audio and video, and the length It is controlled by the user-mode program itself, and it often fails to match the length of the buffer. Therefore, the biggest limitation of RAID 5 is the matching of the stripe cache (stripe buffer in memory) and the user-mode buffer. degree

When RAID 5 finds that the application buffer does not match the stripe cache, it sets the STRIPE_DELAYED flag to delay the delivery of I / O to the stripe in anticipation of subsequent data input. This is a passive waiting process. For a single I / O cannot achieve stripe cache matching, cannot efficiently cooperate with I / O, and has disadvantages such as write amplification of RCW and RMW

[0004] In addition, RAID5 has many design limitations such as interrupting user writing in the failure state and being unable to read the remaining data, and rebuilding the entire disk takes time and I / O resources.

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