Data snapshot method and storage device

Abstract

Embodiments of the invention provide a data snapshot method and a storage device. The method comprises the steps of obtaining a reading frequency of a first logic address in a source LUN (Logic Unit Number) or a snapshot LUN, wherein the first logic address is any logic address in the source LUN and the snapshot LUN; when the reading frequency of the first logic address in the source LUN or the snapshot LUN is greater than a preset frequency, querying a physical address corresponding to the first logic address in the snapshot LUN according to the first logic address; and when the physical address in the snapshot LUN corresponding to the first logic address is not queried, establishing a corresponding relationship between the first logic address in the snapshot LUN and a first physical address in the snapshot LUN, and backing up data, corresponding to the first logic address in the LUN, in the snapshot LUN according to the first physical address. When the first logic address in the snapshot LUN needs to be read, it is not required to read the data in the source LUN, so that unnecessary ground signaling forwarding is avoided and the data reading efficiency is improved.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of storage, and in particular, to a data snapshot method and a storage device. Background technique [0002] With the increasing demand for centralized storage applications, users need to protect data online to shorten the backup window. Snapshot technology is one of the effective ways to prevent data loss for online storage devices. More and more storage devices are starting to This feature is supported. Among them, virtual snapshot is a technology to realize the snapshot function, and copy-on-write (English: Copy on write, COW for short) is an implementation method of virtual snapshot. The specific process is: source logical unit number (English: Logical UnitNumber , referred to as: LUN) stores a mapping table, which records the mapping relationship between the logical address and the physical address of each data on the source LUN. When the virtual snapshot is activated (that is, th...

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Problems solved by technology

[0003] However, in the prior art, data is stored in the snapshot LUN only when the source LUN is written. If no new data is written to a logical address in the source LUN, the logical address in the snapshot LUN will not be stored. For data, when it is necessary to read the logical address in the snapshot LUN, it needs to be redirected to the source LUN to read the data, which causes unnecessary information forwarding and reduces the efficiency of data reading

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