Do I need to backup AWS EBS data? [closed]

Question

I am running a web-app on an AWS EC2 instance that uses EBS storage as its local drive. The web app runs on an Apache/Tomcat server, handles uploaded files in local storage and uses a MySQL database, all on this local drive. Does AWS guarantee the integrity and availability of EBS data or should I back it up to S3? If so, how do I do that? I need to have daily incremental backups (i.e. I can only afford to loose recent transactions/files performed today). Note: I am not worried about human caused errors (accidental deletes, etc.) rather system crashes, underlying service failure, etc. Thanks..

Answer 1

Amazon does not guarantee the integrity of your EBS volumes, but they are very easy to back up. Simply take a daily snapshot (You could set up a cron using ec2-api-tools to do the daily snapshot).

EBS snapshots are stored in S3. They are not in your own bucket and the details are handled by Amazon, but the infrastructure that the snapshots are stored on is S3.

The snapshots are incremental, and back up the entire volume. Each snapshot stores the changes on the device since the last snapshot, so taking them often will reduce how long they take to make, but you can only have a limited number of snapshots at once per AWS account. I think it is 250. You need to delete your old snapshots eventually to deal with that. You could also do that with a cron job. Deleting old snapshots does not invalidate the newer ones even though they are stored as incremental, because it will actually update the next newest snapshot to contain the information from the previous one upon deletion.