Explanation
Why the waste happens and who it affects.
Because billing is based on the total provisioned capacity - not actual usage - this creates ongoing waste when large volumes are only partially used. Overprovisioning may result from default sizing in templates, misestimated requirements, or conservative provisioning practices. Identifying and remediating these cases can lead to meaningful storage cost reductions without impacting workload performance.
Billing model
The pricing dimensions that drive this cost.
Amazon EBS volumes are billed per GB-month of provisioned storage capacity, not based on the amount of data actually stored on the volume. You incur charges for the total provisioned size - even if only a portion of that capacity is used. This pricing model means volumes with low utilization relative to their allocated size can result in unnecessary costs.
How to detect
4 checks to find it in your estate.
- Identify EBS volumes with low storage utilization compared to their provisioned size
- Compare used GB vs. allocated GB for each volume, using a configurable threshold to flag inefficiencies
- Review usage trends to ensure the volume hasn't recently grown or experienced temporary spikes
- Assess whether volume size was inherited from legacy templates or provisioned without sizing analysis
How to fix
3 ways to remove the waste.
- If the volume is attached to a running EC2 instance and can tolerate replacement, create a smaller volume of the same type and migrate the data
- For volumes that cannot be replaced easily, plan to adjust provisioning defaults in AMIs, launch templates, or infrastructure-as-code going forward
- Document sizing assumptions and consider automated checks to catch overprovisioning at creation time
Documentation
Vendor references for pricing and configuration.