Snapshot replication
Replicating a snapshot means saving a copy of the snapshot to another location. In AWS, another location can be one of the following:
different region within the same account.
same region in a different account.
different region within different account.
For example, an AWS cloud administrator have their assets in the region X. The snapshots of those assets will also be stored in X region. However, you can also replicate the snapshots to the Y region within same account or X/Y region in a different account, for an added level of protection. In NBU Snapshot Manager terminology, the original location (X) is the replication source, and the location where snapshots are replicated (Y) is the replication destination.
Replication is performed in three steps. This mechanism is handled internally and the entire process is completely transparent to the user.
Share the snapshot, only if replicating to a cross account. For more information, see the Share a snapshot section of the AWS documentation.
Copy the snapshot. For more information, see the CopySnapshot section of the AWS documentation.
Unshare the snapshot, only if replicating to a cross account.