Amazon Elastic Block Store (Amazon EBS) is a new type of storage
designed specifically for Amazon EC2 instances. Amazon EBS allows you to create
volumes that can be mounted as devices by Amazon EC2 instances. Amazon EBS
volumes behave like raw unformatted external block devices.
They have user supplied device names and provide a block device
interface. You can load a file system on top of Amazon EBS volumes, or
use them just as you would use a block device.
You can create up to twenty Amazon EBS volumes of any size (from one
GiB up to one TiB). Each Amazon EBS volume can be attached
to any Amazon EC2 instance in the same availability zone or can be
left unattached.
Amazon EBS provides the ability to create snapshots of your Amazon EBS volumes
to Amazon S3. You can use these snapshots as the starting point for new Amazon EBS
volumes and can protect your data for long term durability.