Posted On: May 9, 2018
Copies of Amazon Elastic Block Store (Amazon EBS) Snapshots encrypted under a custom Customer Managed Key (CMK) are now incremental. This means that when you make a new copy of an EBS Snapshot, only the modified chunks compared to the previous copy of the same EBS Snapshot are saved in the new copy. This minimizes the time required to copy the EBS Snapshot and saves on storage costs by not duplicating data for such EBS Snapshots encrypted with custom CMK. This is similar to what we already support for copies of unencrypted EBS Snapshots and copies of EBS Snapshots encrypted under your default CMK.
No changes are required at your end to take advantage of this feature. You many continue to use copy-snapshot API as you do normally for making EBS Snapshots. The resulting EBS Snapshot will be incremental if there is already a prior copy of the EBS Snapshot encrypted under the same custom CMK in the destination account/region.
This feature is available in all commercial AWS Regions except AWS China (Beijing) and China (Ningxia) Regions. To learn more about how incremental EBS Snapshots work, visit Amazon EBS Snapshots. For general information about Amazon EBS, visit the service page.