A data snapshot method and device

Abstract

A data snapshot method and device. The method includes: receiving a host's first data write request to the source logical unit number LUN, the first data write request includes the start address and data length to be written into the source LUN storage space; according to the first A data write request, obtaining the first redirected write start address of the first data to be written in the reserved storage space, the size of the reserved storage space is greater than or equal to the source LUN storage space; from the second Starting from a redirected write start address, the first data to be written is written into the reserved storage space. Corresponding devices are also disclosed. The present invention writes the data to be written into the continuous reserved storage space by obtaining the redirected write start address of the data to be written in the reserved storage space when taking a snapshot of the data, which can ensure that the data to be written can be continuous Write to the reserved storage space, so that the snapshot can be backed up immediately without affecting the read and write performance of the source LUN.

Description

technical field [0001] The present invention relates to the field of storage technology, in particular to a data snapshot method and device. Background technique [0002] With the tremendous development of computer technology, the importance of data backup has gradually become prominent. Traditionally, people have been using technologies such as data replication, backup, and recovery to protect important data information, and regularly back up or replicate data. However, the price and cost of this backup method are relatively high, and consume a lot of time and system resources, and the recovery time objective (Recovery Time Object, RTO) and recovery point objective (Recovery Point Object, RPO) of data backup are also very long. Since the data backup process will affect application performance and is very time-consuming, data backup is usually scheduled to be performed when the system load is light (such as at night). In addition, in order to save storage space, full backu...

AI Technical Summary

Problems solved by technology

Although redirection-on-write does not affect the write performance of the host, since the space for redirected writing is randomly allocated by the storage pool, the storage pool cannot understand and guarantee the continuity of the source LUN space, resulting in multiple redirection of the source LUN After writing, the data space changes from continuous to discrete

The read-ahead operation of the cache can only support continuous data space, and cannot pre-read discrete data space

As a result, when the host reads the source LUN, the cache hit rate is very low, and almost all data needs to be read from the hard disk, which reduces the read performance.

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