AWS Certified Solutions Architect Associate Test 1

Data stored in Amazon EBS volumes is redundantly stored in multiple physical locations as part of normal operation of those services and at no additional charge.
However, Amazon EBS replication is stored within the same availability zone, not across multiple zones; therefore, it is highly recommended that you conduct regular snapshots to Amazon S3 for long-term data durability.
For customers who have architected complex transactional databases using EBS, it is recommended that backups to Amazon S3 be performed through the database management system so that distributed transactions and logs can be checkpointed.
AWS does not perform backups of data that are maintained on virtual disks attached to running instances on Amazon EC2.
Reference:
http://d0.awsstatic.com/whitepapers/Security/AWS%20Security%20Whitepaper.pdf