Data recovery method, device and system

Abstract

The embodiment of the invention provides a data recovery method, device and system. And the first server receives the metadata of the first data fragment sent by the second server, wherein the metadata of the first data fragment comprises first indication information which is an identifier or a storage position of a backup data fragment of the first data fragment in the first server. And when thefirst server confirms that the first server does not store the backup data fragment of the first data fragment in the first server according to the metadata of the first data fragment, the first server requests the second server for the backup data fragment of the first data fragment in the second server, and stores the backup data fragment of the first data fragment. The data size of the identification of the backup data fragment of the first server or the storage position of the backup data fragment of the first server stored in the metadata is smaller than the data size of the hash value. Therefore, few network resources are used for transmitting a large amount of metadata from the second server, and the data recovery efficiency is improved.

Description

technical field [0001] The embodiments of the present invention relate to the field of data recovery, and in particular, to a data recovery method, device and system. Background technique [0002] Existing data backup methods include local backup and remote backup. Compared with local backup, remote backup improves the reliability of backup data. When restoring local data, users can restore local data based on local backup data or remote backup data. In order to improve the utilization rate of local storage resources, local expired backup data will be continuously deleted locally. [0003] There are two traditional data recovery methods. The first method is that the local server reads all the backup data from the remote end, and then saves all the backup data locally. The second method is for the local server to confirm whether there is backup data locally. For the backup data that exists locally, it does not need to be read from the remote end. For the backup data that do...

AI Technical Summary

Problems solved by technology

[0004] Using the first data recovery method to restore data requires all backup data to be transmitted through the network. The amount of data transmitted during recovery is large and consumes network resources.

Using the second data recovery method to restore data requires dividing the backup data into several data fragments in advance, performing hash operations on each data fragment and saving the hash value of each data fragment. The operation is complex and expensive to process. Resources, and the hash value of data fragmentation occupy a large byte space, consuming local and remote storage resources

In addition, when using the second data recovery method to restore data, the hash values ​​of all data fragments of the backup data read from the remote end need to be cached locally, which requires network resources and local cache resources

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