Unarchived Long-Term EBS Snapshots

Explanation

EBS Snapshot Archive is a lower-cost storage tier for rarely accessed snapshots retained for compliance, regulatory, or long-term backup purposes. Archiving snapshots that do not require frequent or fast retrieval can reduce snapshot storage costs by up to 75%. Despite this, many organizations retain large volumes of snapshots in the standard tier long after their operational value has expired.

Relevant Billing Model

Charged per GB-month of snapshot data stored, with pricing dependent on whether the snapshot is in the standard tier or the lower-cost archive tier

Detection

• Identify EBS snapshots that are more than 90 days old and have not been accessed or restored
• Review backup policies or compliance requirements that justify long-term retention
• Evaluate whether snapshots are one-time or periodic backups that are unlikely to be used operationally (e.g., end-of-project, monthly compliance snapshots)
• Check for large volumes of retained snapshots from now-defunct workloads or projects

Remediation

• Archive eligible snapshots using the `ModifySnapshotTier` API, AWS CLI, or console
• Confirm organizational retention policies before archiving
• Ensure teams understand how to restore archived snapshots and the longer retrieval times involved
• Educate teams on snapshot lifecycle and the impact of incremental chaining for efficient archive selection