AWS Difference between a snapshot and AMI

Question

So I am having trouble working out what, specifically is the difference between these two.

As I understand it, a snapshot is simply a backup of the disk drive, where

Answer 1

Here are few more differences between AMI and EBS Snapshots:

1) An AMI is launchable and contains links to the root device and may contain links to snapshots of the other data volumes.

2) The data image contained in an AMI does not represent a well-defined point-in-time, unless the instance is rebooted, something that is typically not acceptable for production environment. Snapshots can be taken in a consistent manner since their exact point-in-time can be controlled, so before the snapshot starts it can be made sure that everything is "ready for backup".

3) An AMI can be created from existing snapshots of the root device for Linux but not for Windows.

Answer 2

From the definition provided by AWS it clarifies the difference - An Amazon Machine Image (AMI) is a template that contains a software configuration (for example, an operating system, an application server, and applications). From an AMI, you launch an instance, which is a copy of the AMI running as a virtual server in the cloud. Whereas for Snapshots You can back up the data on your EBS volumes to Amazon S3 by taking point-in-time snapshots. Snapshots are incremental backups, which means that only the blocks on the device that have changed after your most recent snapshot are saved. When you delete a snapshot, only the data exclusive to that snapshot is removed.

Answer 3

The major difference is between the type of service referred to. A snapshot is of an EBS volume where you are able to save state and reboot with the same data at a certain point in time.

An AMI is similar, but its for the EC2 instances themselves. You cannot take a snapshot of a non ebs backed instance, but you can create a AMI (system image) of one.

Generally I use EBS snapshots as backup solutions for a database volume and I use an AMI to save instance configuration

Answer 4

Snapshots are less expensive to use as a backup strategy, because when you have multiple snapshots, you only pay for one full backup and ther rest are, in essence, just diffs, and usually much smaller.