AWS Four DR scenarios

There are four DR scenarios that highlight usage of AWS in a DR and a 'HA-lite' situation:

•  Backup and Restore - For systems running on AWS, customers also back up into Amazon S3. Snapshots of Elastic Block Store (EBS) volumes and backups of Amazon RDS are stored in Amazon S3. Alternatively, you can copy files directly into Amazon S3, or you can choose to create backup files and copy them to Amazon S3.
• Pilot Light for Simple Recovery into AWS - This scenario is similar to a Backup and Restore scenario, however, you must ensure that you have the most critical core elements of your system already configured and running in AWS (the pilot light). When the time comes for recovery, you would then rapidly provision a full scale production environment around the critical core. The database data would be replicated to S3. You would typically have some pre-configured servers bundled as Amazon Machine Images (AMIs), which are ready to be started up at a moment’s notice.  These servers could be EC2 instances that have been stopped.
• Warm Standby Solution - A warm standby solution extends the pilot light elements and preparation. It further decreases the recovery time because in this case, some services are always running. By identifying your business-critical systems, you would fully duplicate these systems on in another AWS zone or region and have them always on.  This would insure that the EC2 capacity is available in a disaster.
•  Active-Active Solution - A multi-site solution runs in another AZ or zone in an active-active configuration. The data replication method that you employ will be determined by the recovery point (RPO) you choose.