Amazon EC2 Root device - EBS-backed VS Instance store-backed

When launching a EC2 instance, it is very important to know if the root device is EBS-backed or instance store-backed. The major difference lies in what happens to the data when an instance is terminated.

In an EBS-backed root device, when the instance terminates, the data in the root volume would persist.

In an instance store-backed root device, when the instance terminates, the data would be gone.

Detailed Comparison:

Characteristic	Amazon EBS-Backed	Amazon instance store-backed
Boot Time	Usually less than 1 minute	Usually less than 5 minutes
Size Limit	1 TiB	10 GiB
Root Device Volume	Amazon EBS volume	Instance store volume
Data Persistence	Data on Amazon EBS volumes persists after instance termination; you can also attach instance store volumes that don't persist after instance termination	Data on instance store volumes persists only during the life of the instance; you can also attach Amazon EBS volumes that persist after instance termination
Upgrading	The instance type, kernel, RAM disk, and user data can be changed while the instance is stopped.	Instance attributes are fixed for the life of an instance
Charges	Instance usage, Amazon EBS volume usage, and Amazon EBS snapshot charges for AMI storage	Instance usage and Amazon S3 charges for AMI storage
AMI Creation/Bundling	Uses a single command/call	Requires installation and use of AMI tools
Stopped State	Can be placed in stopped state where instance is not running, but the instance is persisted in Amazon EBS	Cannot be in stopped state; instances are running or terminated

Check the AMI basics guide for more details.