COW (Copy On Write) snapshoot data brushing and writing method based on linux system and system thereof

Abstract

The invention discloses a COW (Copy On Write) snapshoot data brushing and writing method based on a linux system. The method comprises the steps of performing CPW snapshoot operation when IO data are written, and storing generated exception information into a snapshoot data block of a memory; judging whether the snapshoot data block meets a preset brushing and writing condition, and brushing and writing the exception information in the snapshoot data block into a magnetic disk in a unified mode if the snapshoot data block meets the preset brushing and writing condition. The COW snapshoot data brushing and writing method can greatly reduce magnetic disk access times without affecting the CPW snapshoot performance, improves the IO processing speed, and prevents the performance of the linux system from being affected as much as possible. The invention further discloses a COW snapshoot data brushing and writing system based on the linux system. The COW snapshoot data brushing and writing system also has the advantages the same as those of the COW snapshoot data brushing and writing method.

Description

technical field [0001] The invention relates to the technical field of snapshots, in particular to a COW snapshot data flashing method based on a linux system and a system thereof. Background technique [0002] In the linux system, when the IO data is written to a storage location in the source volume of the linux system for the first time, a COW (Copy On Write, copy-on-write) snapshot operation will be executed. The content of the COW snapshot operation is: first Read the original content of the location, copy it to a location in the destination volume, and then write the IO data to the location; that is, when new data is written, the old data is stored to avoid data overwriting To another location, and this process will generate an exception message containing the location mapping relationship (between data blocks) of the old and new data. Every time the current COW snapshot operation is executed, the generated exception information will be flushed to the disk. [0003] ...

AI Technical Summary

Problems solved by technology

[0003] Because in the above operations, the COW snapshot operation is performed on data blocks, if the size of the data blocks in the source volume is small (for example, 4KB), and the written IO data is large (for example, 20G), then an IO Write operations will need to perform multiple COW snapshot operations, generating multiple exception information, so the number of disk accesses in this case is very large, and frequent disk access will slow down the processing speed of IO and affect the performance of the Linux system

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