EBS - Restore from Snapshot

Question

When restoring an EBS volume from snapshot can you use the latest snapshot only (i.e. the one with the last incremental block changes) and do you need to have kept all previous snapshots (including the orginal)?

This seems to suggest you can but want to check http://www.nimbo.com/blog/observations-ebs-snapshot-restore-behavior-aws/

So as an example, I have a RAID 0 with 4 EBS volumes I snapshot day 1. I take daily snapshots for several months with an S3 lifecycle policy that deletes snapshots after 1 month. Month 3 i want to restore these volumes to a day in month 2 to be used by a seperate instance. Will this work? Or do i need a history of all the snapshots?

Answer 1

First, EBS snapshots are stored in S3, but not in any S3 bucket that you have control of. You can't use S3 lifecycle policies to control EBS snapshot retention. You have to use the EBS API or console to manage EBS snapshots.

Given that, AWS manages your EBS snapshot history for you. Any EBS snapshot that exists in your account is able to be restored, and does not depend on you having kept previous snapshots around. When you delete a historical snapshot that another snapshot depends on, Amazon handles that behind the scenes in such a way that you can still restore any snapshots you haven't deleted.