I'm specifically looking at the Standard Large On-Demand instance which has 850 GB of instance storage.
What I really don't understand is why have 850 GB of storage on the instance if that data will disappear as soon as the instance is shut down and/or destroyed.
It seems like EBS is the standard way of having permanent disk space for instances, including root volumes. You can stripe them. You can back them up in different availability zones and/or S3 and/or off of Amazon's system completely.
Why keep anything at all on the instance storage if you would have to back it up frequently off-instance (EBS/S3?) to avoid losing it all? Is it a speed advantage even beyond what striping EBS volumes would give you?
It seems like the best configuration for safety and ease of setup would be to just not use the instance storage at all, and to have instead striped EBS volumes with backup to S3 or off site.
Am I right, or is there a good reason for using that 850 GB of instance storage?