A. Data synchronization, save the data at the specified time of the cloud hard disk, and you can set automatic backup. If you delete the cloud disk that created the backup, the corresponding backup will not be deleted at the same time, the snapshot also saves the data of the cloud disk at a specified time, if you delete the cloud disk that created the snapshot, the corresponding snapshot will also be deleted at the same time

B. Disaster recovery scope, backup and VS are located in the same availability zone, cloud server backup supports cross-region replication, snapshots and VS are located in different availability zones

C. Business recovery, by restoring the backup to the cloud hard drive, or creating a new cloud hard drive through the backup, snapshots are rolled back to the cloud hard drive, or creating a new cloud hard drive through the snapshot

D. Storage scheme, backup and cloud hard disk data are stored separately and stored in object storage, snapshots are stored together with cloud hard disk data