title: Amazon EBS, snapshots as incremental backups
body: <p>I'm working on an automated mechanism for our EBS volumes to be backed up on a daily basis. </p>
  
  <p>I know quite well the steps to create a new snapshot. Apparently it's all quite simple, you have an EBS volume which you can snapshot, and you can restore the snapshot anytime. Fine.</p>
  
  <p>But my concern is about the size of the snapshots, I know these snapshots are stored with compression in S3, and we're going to be charged depending on the size of the snapshots. If we have large amounts of data we'll have a significant amount increase in the invoice for each backup we make.</p>
  
  <p>However, according to Amazon's pages, these snapshots are incremental. That'd solve my problem as the daily backup would only upload the data which has changed since the last snapshot. But this leads me to next question: if the backup is incremental and we're only uploading the modified data, where's the original data being stored? (ie. the first snapshot which obviously couldn't have been done incrementally...)</p>
  
  <p>Unfortunately I haven't been able to find this information all over Amazon's documents.</p>
  
  <p>Does anybody have experience with snapshots and its billing?</p>
  
  <p>I'd appreciate any help, thanks!</p>