Help Center/ Elastic Volume Service/ User Guide/ Overview/ Differences Between EVS Disk Backup and EVS Snapshot

Updated on 2022-12-20 GMT+08:00

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Differences Between EVS Disk Backup and EVS Snapshot

Both EVS disk backup and EVS snapshot provide redundancies for the EVS disk data to improve reliability. Table 1 lists the differences between them.

**Table 1** Differences Between Backups and Snapshots
Metric	Storage Solution	Data Synchronization	DR Range	Service Recovery
Backup	Backups are stored in OBS, instead of disks. This ensures data restoration upon disk loss or corruption.	A backup is a copy of a disk at a given point in time and is stored in a different location. Deleting a disk will not clear its backups.	A backup and its source disk reside in different AZs.	To restore data and recover services, you can restore the backups to their original disks or create new disks from the backups.
Snapshot	Snapshots are stored on the same disk as the original data. NOTE: Creating a backup requires a certain amount of time because data needs to be transferred to OBS. Creating or rolling back a snapshot consumes less time than creating a backup.	A snapshot is the state of a disk at a specific point in time and is stored in the same disk. If the disk is deleted, all its snapshots will also be deleted. For example, if you reinstalled or changed the server OS, snapshots of the system disk were also automatically deleted. Snapshots of the data disks can be used as usual.	A snapshot and its source disk reside in the same AZ.	You can use a snapshot to roll back its original disk or create a disk from the snapshot.