S3 bucket size unexpectedly large – possible noncurrent versions issue

Can you please share more details on the current Lifecycle Policy?

I would recommend referring to below AWS Storage Blog, which explains the current Lifecycle configurations required to reduce storage costs for non-current versions. [+] Reduce storage costs with fewer noncurrent versions using Amazon S3 Lifecycle: https://aws.amazon.com/blogs/storage/reduce-storage-costs-with-fewer-noncurrent-versions-using-amazon-s3-lifecycle/

Yes: Here is the screenshot of lifecycle settings

Thank you for sharing.

Looking at the Rule, you have overlapping Lifecycle configurations for non-current versions. Please Note: When you have multiple rules in an S3 Lifecycle configuration, an object can become eligible for multiple S3 Lifecycle actions on the same day. In such cases, Amazon S3 follows these general rules: Permanent deletion takes precedence over transition. Transition takes precedence over creation of delete markers. When an object is eligible for both an S3 Glacier Flexible Retrieval and an S3 Standard-IA (or an S3 One Zone-IA) transition, Amazon S3 chooses the S3 Glacier Flexible Retrieval transition. [+] https://docs.aws.amazon.com/AmazonS3/latest/userguide/lifecycle-conflicts.html

From my observation:

1. Why are you moving the non-current versions to Glacier Flexible Retrieval.? The minimum storage duration for objects in S3 Glacier Flexible Retrieval storage class is 90 days. [+] https://docs.aws.amazon.com/AmazonS3/latest/userguide/glacier-storage-classes.html#GFR

If you are looking to clean up all non-current versioned objects, then my suggestion will be to create a Lifecycle rule only for Non-current versions actions.

Also, create a dedicated Rule for Delete expired object delete markers or incomplete multipart uploads, this way you are not overlapping multiple actions in a single rule.

Thanks. This happened only because I had previously 90 days for Glacier storage, but because noncurrent versions started to stack up, I change it temporarily to 1 day, because i want to get rid of noncurrent versions. I changed it as you advised now. I also created separate rule for deleting expires/incomplete multipart uploads. I think this together with limiting number of noncurrent versions to 0, which I changed previously, will solve my problem. Thanks for help.