Updated 25 October 2026 · Published by Zoorik
An EBS volume is a block-level storage device you attach to an EC2 instance, a virtual machine (VM) in AWS. Once attached, the volume works like a physical hard drive. EBS stands for Amazon Elastic Block Store.
An EBS volume in AWS can be the system drive, or hold data such as a database. Two rules apply:
- It must share its instance’s Availability Zone.
- Its “Delete on termination” setting decides if it’s deleted or kept when the instance is terminated.
An example of EBS in AWS
Say your database runs on a 500 GiB data volume of type gp3, a General Purpose SSD (solid-state drive). The database writes 200 GiB.
AWS bills all 500 GiB. With EBS, you pay for what you provision, not what you write.
Why it matters for your bill
- EBS bills each GB you provision, every month, until you delete the volume.
- A volume kept after its instance ends still bills.
- You can grow a volume in place, then extend its file system.
- AWS says “You can’t decrease the volume size.” So a volume sized for an old peak keeps billing at that size.
- To shrink an EBS volume, you copy the data to a new, smaller one with a tool such as rsync or robocopy.
Amoeba moves a VM’s data disks onto one pool sized to your data, then rightsizes it autonomously. It works on EBS data volumes on Windows and Linux VMs, never the root volume.
The free assessment works out your own figure.
Read next: How to shrink an EBS volume when AWS only lets it grow
Sources: AWS, “Amazon EBS volumes” (opens in a new tab); AWS, “Amazon EBS pricing” (opens in a new tab); AWS, “Modify an Amazon EBS volume using Elastic Volumes operations” (opens in a new tab); AWS, “Preserve data when an instance is terminated” (opens in a new tab).