LearnGlossary

What is instance store in AWS?

Updated 26 October 2026 · Published by Zoorik

Instance store in AWS is temporary block storage for an EC2 instance, a server in AWS. Its disks are physically attached to the instance’s host computer. You see it as one or more instance store volumes.

AWS says it suits data that changes often, such as caches and scratch data. Not every instance type has it.

A reboot keeps the data. It’s lost when the instance stops, hibernates or terminates, or when AWS retires or recovers it. If a disk fails, its data is lost.

A reboot keeps instance store data. A stop, hibernate or terminate loses it. Illustration of documented behaviour, with no measurements. A box labelled Instance store volume sits on the left, with four arrows leading right. The top arrow, labelled Reboot, is drawn in navy and ends at a box labelled Data kept, which carries a green tick. Three arrows, labelled Stop, Hibernate and Terminate, end at one box labelled Data lost, which carries a red dot. A reboot keeps instance store data. A stop, hibernate or terminate loses it. Instance store volumeRebootData keptStopHibernateTerminateData lost
Illustration of documented behaviour, not a measurement: what a reboot, a stop, a hibernate and a terminate do to data on an EC2 instance store volume, which is also lost when AWS retires or recovers the instance, or when a disk fails.

An example: a cache on instance store

Say a web server keeps its cache on an EC2 instance store volume. After a reboot, the cache is still there. After an overnight stop, it starts with a blank volume.

Instance store vs EBS

  • An instance store volume exists only for the life of its instance. An Amazon Elastic Block Store (EBS) volume persists on its own.
  • You get instance store only at launch. You can’t detach it and attach it to another instance.

Why it matters for your cloud cost

There’s no extra charge in AWS instance store pricing. The volumes are part of the instance’s usage cost. Data you need to keep belongs on storage such as EBS or Amazon S3, which cost extra.

  • EBS storage is charged per provisioned GB each month, empty or not, until you delete the volume.
  • A change of instance type loses instance store data, so plan for it before you switch a node group’s type.

The free assessment works out what your disks could save.

Read next: How to change an EKS node group instance type

Sources: AWS, “Instance store temporary block storage for EC2 instances” (opens in a new tab); AWS, “Data persistence for Amazon EC2 instance store volumes” (opens in a new tab); AWS, “Amazon EBS volumes” (opens in a new tab); AWS, “Amazon EBS pricing” (opens in a new tab).

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