Incremental snapshot method and device

Abstract

The invention provides an incremental snapshot method and device. The method comprises the following steps: when a snapshot source volume needs to be subjected to data write operation, finding a latest created snapshot according to a snapshot linked list of the snapshot source volume to be written, confirming that COW mapping is stored in a copied COW volume during writing of the latest created snapshot, and writing data to be written into the corresponding sectors of the snapshot source volume; when the snapshot needs to be subjected to data read operation, judging whether the snapshot to be read has the COW mapping in the COW volume or not, and if so, reading the corresponding data to be read from the COW volume according to the COW mapping of the snapshot to be read; otherwise, searching the latest created snapshot associated with the snapshot to be read according to a snapshot linked list of the snapshot to be read, and reading the corresponding data to be read from the snapshot source volume according to the COW mapping of the latest created snapshot. According to the method, the storage space and cost are reduced, the risk of complicated storage management is lowered, and the storage management operation is convenient.

Description

technical field [0001] The invention relates to the technical field of storage disaster recovery, in particular to an incremental snapshot method and device. Background technique [0002] With the rapid development of computer technology, digital information has gradually replaced paper media data, showing rapid growth. Massive data has led to the development of cloud computing, big data and mass storage systems, and the demand for storage devices and storage applications is also increasing. Government industries, banking systems, and power companies have high requirements for data security and business continuity, and online data protection must be provided. [0003] Snapshot (Snapshot) is an effective method for online storage devices to prevent data loss. One function of snapshots is to back up and restore online data on demand. When an application failure or file damage occurs on the storage device, fast data recovery can be performed, and the data can be restored to ...

AI Technical Summary

Problems solved by technology

[0004] The traditional snapshot technology is to perform a single mapping and protection for the data state of each storage resource at a time point, so that the snapshot can be restored directly. However, since the snapshots at different time points are not associated, there are many redundant copies when creating multiple snapshots. On the one hand, the storage capacity becomes larger and the storage cost is higher; on the other hand, when data modification is performed on the snapshot source volume, the corresponding multiple snapshots also need to be modified, and the operation is complicated

[0005] In addition, the traditional snapshot technology is a snapshot for each point in time, and the mapping relationship between the source data and the written data of each snapshot needs to be stored in an independent volume

When the number of snapshots increases, more and more volumes are required, which undoubtedly brings problems such as complex storage management and high storage costs.

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