In the dynamic landscape of AWS, EC2 snapshots play a vital role in data protection and disaster recovery strategies. However, as your cloud infrastructure expands, the costs associated with these seemingly affordable snapshots can quickly escalate if left unchecked. This blog post explores the intricacies of snapshot management, focusing on identifying idle snapshots, understanding snapshot types, and implementing cost-effective practices to optimize your AWS environment.

The Snapshot Cost Pitfall

One of the most common challenges AWS users face is underestimating the details of the cloud cost. Understanding why AWS charges specific amounts for specific resources, and in the case of snapshots, underestimating the cumulative cost impact of snapshots. While individual snapshots may appear inexpensive, the aggregated cost of numerous snapshots over time can become a significant burden on your budget. This is particularly evident when snapshots are created frequently and left unmanaged, resulting in a proliferation of idle snapshots that silently consume resources and drive up costs.

Identifying Idle Snapshots

To effectively combat the cost escalation caused by idle snapshots, it is crucial to regularly assess your snapshot inventory. Idle snapshots are those that are no longer required or utilized, yet they continue to occupy storage space and contribute to rising costs. A common approach to identify idle snapshots is to establish an age threshold, such as 90 days, and consider snapshots older than this threshold that have not been used for creating new instances or restoring data as candidates for cleanup.

By proactively identifying and removing these idle snapshots, you can optimize storage utilization and maintain cost efficiency.

Understanding Snapshot Types

EC2 snapshots are categorized into two primary types: Regular Snapshots and Amazon Machine Images (AMIs). Understanding the distinct characteristics and use cases of each type is essential for effective snapshot management.

1. Regular Snapshots:

  • Capture the point-in-time state of an EC2 instance’s EBS volumes.
  • Employ incremental backup, storing only the changed blocks since the previous snapshot.
  • Primarily used for data backup and restoration purposes, as well as creating new EBS volumes.

2. AMIs:

  • Comprehensive snapshots that encapsulate all the necessary information to launch an EC2 instance.
  • Include a template for the root volume, launch permissions, and block device mapping.
  • Enable the creation of new instances with the same configuration as the source instance.

Automated vs. Manual Snapshots

The method of creating snapshots, whether automated or manual, has a direct impact on cost efficiency.

1. Automated Snapshots (Incremental):

  • Generated using AWS Backup or services like Amazon Data Lifecycle Manager (DLM).
  • Leverage incremental backup by default, capturing only the changes since the last snapshot.
  • Incur charges based on the delta (changed data), resulting in cost optimization.

2. Manual Snapshots (Full):

  • Created manually using the AWS Management Console, CLI, or SDKs.
  • Capture the entire contents of the EBS volume with each snapshot.
  • Incur charges based on the full size of the snapshot, potentially leading to higher storage costs.

It is important to note that the initial snapshot of an EBS volume is always a full snapshot, regardless of the creation method.

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AWS Snapshot Charging Overview

AWS charges for EC2 snapshots based on the amount of storage space your snapshots use in Amazon S3. However, the charging is not straightforward per-gigabyte storage; it’s based on the differential storage between snapshots:

  • Initial Snapshot: You’re charged for the storage of the entire volume data that the snapshot contains.
  • Subsequent Snapshots (Incremental): You are charged only for the additional data (delta) that new or changed blocks represent.

Example of Incremental Snapshot Costs:

Let’s say you have an EBS volume with 100 GB of data. You create an initial snapshot (Snapshot 1) of this volume, which will be a full snapshot. At this point, you’ll be charged for the storage of the entire 100 GB.

Now, suppose you add 20 GB of new data to the volume and then create a second snapshot (Snapshot 2). Snapshot 2 will only contain the incremental changes since Snapshot 1, i.e., the 20 GB of new data. You’ll be charged for the additional 20 GB used by Snapshot 2, bringing your total snapshot storage cost to 120 GB (100 GB for Snapshot 1 + 20 GB for Snapshot 2).

If you create a third snapshot (Snapshot 3) after modifying 10 GB of the original data and adding 5 GB of new data, Snapshot 3 will only contain the incremental changes of 15 GB (10 GB modified + 5 GB added). Your total snapshot storage cost will now be 135 GB (100 GB for Snapshot 1 + 20 GB for Snapshot 2 + 15 GB for Snapshot 3).

This demonstrates how subsequent snapshots after the initial one only capture incremental changes, helping optimize storage costs.

Impact of Deleting Snapshots

When you delete a snapshot, AWS does not necessarily delete all the data in that snapshot. Instead, it only deletes the data exclusive to that snapshot and not used by any other snapshots. Here’s how this impacts costs:

  • Deletion of an Older Snapshot: Suppose you have three snapshots (Snap1, Snap2, and Snap3) and you decide to delete Snap1. If blocks from Snap1 are not needed by Snap2 or Snap3, they are deleted. If Snap1 contains unique blocks that are required by Snap2 or Snap3, these blocks are preserved, and you continue to be charged for them.
  • Cost Impact: Deleting Snap1 might not reduce your storage costs much if Snap2 and Snap3 rely heavily on the data initially backed up in Snap1. In some cases, if Snap1 held a lot of unique data that later snapshots do not use, deleting it could decrease costs.

Remediating Idle Snapshots

To maintain cost efficiency and a clean AWS environment, it is imperative to regularly remove idle snapshots:

1. Regular Snapshots:

  • Utilize the AWS Management Console or CLI to delete the snapshot.
  • Verify that the snapshot is not associated with any instances or AMIs prior to deletion.

2. AMIs:

  • Deregister the AMI using the AWS Management Console or CLI before deleting the associated snapshot.
  • Verify the absence of any running instances launched from the AMI and create a new AMI if necessary.
  • Ensure that the AMI has not been used to launch instances within a specified timeframe.

By customizing your snapshot management workflow with, you can strike the perfect balance between automation and human control, ensuring cost optimization without compromising on oversight.


AWS EC2 snapshots may appear cost-effective on an individual basis, but the aggregated costs can quickly spiral out of control if left unchecked. By understanding the different types of snapshots, proactively identifying idle ones, and leveraging automation tools like Wiv, you can effectively manage your snapshot lifecycle and keep costs under control. Remember, in the world of cloud computing, every cent counts, and implementing a robust snapshot management strategy is crucial for long-term cost optimization and operational efficiency.