S3 Versioning Overview

Once you enable Versioning for a bucket, S3 preserves existing objects anytime you perform a PUT, POST, COPY, or DELETE operation on them. You can enable versioning while creating an object or later from the Properties tab of the bucket.

Important notes on versioning

1. The bucket owner, the AWS account that created the bucket (root account), and all authorized IAM users can enable versioning.

2. Only the owner of an S3 bucket can permanently delete a version.

3. If you delete an object, you can restore it. If you delete a version, you cannot restore it.

4. You can set Lifecycle rules to manage the lifetime and the cost of storing multiple versions of your objects.

5. S3 Lifecycle management can work with or without enabling versioning.

6. Pricing: Normal S3 rates apply for every version of an object stored or requested. 

7. Versioning’s MFA Delete capability can be used to provide an additional layer of security while deleting versions.

Notes on MFA Delete

1. Versioning’s MFA Delete capability uses multi-factor authentication for deleting versions permanently in addition to the standard AWS account credentials based authentication. 

2. You can enable MFA delete using the Amazon Rest API for S3 or the bucket explorer.

3. Only the bucket owner (root account) can enable MFA delete.

4. Once you enabled MFA delete, all future requests to change the versioning state or delete a version will require the request header x-amz-mfa .

   1. `With every Delete Object Rest API request you also must send registered MFA Device's Serial Number and its AuthenticationCode.