Differences Between EVS Backups and EVS Snapshots¶
Both EVS backups and EVS snapshots provide redundancies for improved disk data reliability. Table 1 lists the differences between them.
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 point of 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. |
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 its original disk or create a disk from the snapshot. |