Skip to main content
NetApp Knowledge Base

Why is the data size of Amazon S3 larger than the logical size of the volume when using Fabric Pool?

  1. Last updated
    Apr 4, 2025
  2. Save as PDF
Views:
820
Visibility:
Public
Votes:
0
Category:
cloud-volumes-ontap-cvo
Specialty:
core
Last Updated:
4/4/2025, 6:19:01 PM

Applies to

  • Cloud Volume ONTAP (CVO)
  • Amazon Web Services (AWS)
  • Fabric Pool
  • Azure

Answer

This is by the design of Object Deletion and Defragmentation.

  • Storage efficiencies such as compression, deduplication, and compaction are preserved when moving data to the cloud tier, reducing object storage and transport costs.
  • But Fabric Pool does not delete blocks from attached object stores. Instead, Fabric Pool deletes entire objects after a certain percentage of the blocks in the object are no longer referenced by ONTAP.

Example: 

There are 1,024 4KB blocks in a 4MB object tiered to Amazon S3. 
Defragmentation and deletion do not occur until less than 205 4KB blocks (20% of 1,024) are being referenced by ONTAP.
When enough (1,024) blocks have zero references, their original 4MB objects are deleted, and a new object is created.

Additional Information

This percentage, the unreclaimed space threshold, can be customized, the default settings are 20% for Amazon S3.

 

 

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.