Differences Between Disk Backups and Disk Snapshots

Both disk backups and disk snapshots provide redundancies for improved disk data 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 damage or corruption.	A backup is a copy of a disk taken at a given time and is stored in a different location. Automatic backup can be performed based on backup policies. Deleting a disk will not delete 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.
Legacy 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 on 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 data to its source disk or create a new disk.
Standard Snapshot	Snapshots are stored in OBS, instead of disks. This ensures data restoration upon disk damage or corruption.	A snapshot is the state of a disk at a specific point in time and is stored in OBS. If a disk is deleted, all its snapshots will not be deleted.	A snapshot and its source disk reside in different AZs.	You can use a snapshot to roll back data to its source disk or create a new disk. The data reliability is high.