A company runs an application on an EC2 instance that uses instance store volumes for scratch data. An engineer stops the instance overnight to save costs. What happens to the data on the instance store volumes?
- The data persists and is available when the instance starts again
- The data is automatically backed up to Amazon S3
- The data is lost when the instance is stopped
- The data is migrated to an EBS volume
Correct answer: C. The data is lost when the instance is stopped
Instance store volumes are physically attached ephemeral storage. Their contents survive an OS reboot but are lost whenever the instance is stopped, hibernated, or terminated, because the instance may be moved to different underlying hardware. There is no automatic backup to S3, and no automatic migration to EBS; both would require the engineer to set up copies explicitly. This is why instance store suits only temporary data such as caches, buffers, and scratch space, while anything that must persist belongs on EBS or S3. A common exam trap is confusing reboot (data survives) with stop (data lost).
Source: AWS EC2 docs: Amazon EC2 instance store — lifetime of instance store data