A method and device for backing up a virtual disk

Abstract

The invention aims at providing a method and a device used for backing-up a virtual disk. The method comprises the steps that when write operation is carried out on the virtual disk, the modification indicating information of at least one storage unit corresponding to the write operation is marked as a modified state; the data of one or a plurality of storage unit(s) with the modification indicating information being marked as the modified states are backed-up to a backup disk. The method and the device have the advantages that write operation is not needed in the operation process on the disk to be backed-up by a user, the read-write frequency of the disk is reduced, a backup space is allocated only according to the modified blocks, the condition that the backup disk is too large or too small can be effectively avoided, and the use ratio of a storage space is improved.

Description

technical field [0001] The invention relates to the field of computer technology, in particular to a method and device for backing up a virtual disk. Background technique [0002] In the prior art, backup methods for virtual machine disks generally use snapshots to store incremental data, but because the size of the backup data cannot be predicted, the backup method according to the prior art cannot determine the required size of the device when creating the backup device , therefore, when it is found that the incremental data exceeds the size of the backup device, the backup device can only be invalidated or expanded again. In the prior art, there is a method for incremental backup using copy-on-write (COW, Copy on Write) technology. However, this technology needs to use an additional disk to support the COW technology, so that data can be written to the disk when data changes occur. COW, and when the data reaches the preset threshold, update the data to the backup disk. ...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, snapshots are generally used to store incremental data in virtual machine disk backup methods, but since the size of the backup data cannot be predicted, according to the existing The technical backup method cannot determine the required size of the device when creating the backup device. Therefore, when it is found that the incremental data exceeds the size of the backup device, the backup device can only be invalidated or expanded again

In the prior art, there is a method for incremental backup using copy-on-write (COW, Copy on Write) technology. However, this technology needs to use an additional disk to support the COW technology, so that data can be written to the disk when data changes occur. In COW, and when the data reaches the preset threshold, update the data to the backup disk

Therefore, based on the above-mentioned unmeasurable incremental data size, the solution using COW technology also needs to occupy a large amount of additional disk space to support this technology

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