This inefficiency arises when snapshots are retained long after they’ve served their purpose. Snapshots may have been created for backups, migrations, or disaster recovery plans but were never deleted—even after the related workload or volume was decommissioned. Over time, these unused snapshots accumulate, continuing to incur storage costs without providing operational value.
EBS snapshots are billed per GB-month for the total data stored. The first snapshot is a full backup; each subsequent snapshot stores only the changed blocks. However, all retained snapshots contribute to cost, since any unchanged data still referenced by newer snapshots keeps the original snapshot from being fully discarded.
Identify snapshots that have not been used to create a new volume or AMI over a defined lookback period Review snapshot tags, descriptions, and creation context to assess whether they were part of a temporary workflow or a long-term retention strategy Check whether the associated volume or instance still exists, or if the snapshot has become orphaned Validate whether the snapshot is still required for compliance, recovery, or audit purposes
Delete snapshots that are no longer needed or are linked to resources that no longer exist. Where retention is required but access is unlikely, document the business reason and implement lifecycle policies to automatically expire outdated snapshots. Consider tagging new snapshots with creation intent and retention timelines to support better cleanup workflows in the future.
