Skip to main content
NetApp Knowledge Base

In what scenario are objects removed or deleted from the cloud tier

Views:
871
Visibility:
Public
Votes:
1
Category:
ontap-9
Specialty:
core
Last Updated:

 

Applies to

  • ONTAP 9.4 and later
  • FabricPool

Answer

TR-4598 FabricPool best practices pg 18

Object deletion and defragmentation

FabricPool does not delete blocks from attached object stores. Instead, FabricPool defragments objects based on the percentage of used blocks in the object.

  • Defragmentation reclaims space that is used by blocks that have been deleted or that are no longer being referenced by ONTAP's local tier
  • Defragmentation and deletion do not occur until less than the unreclaimed space threshold being referenced by ONTAP is met.
    • When enough (1,024) blocks have zero references, their original 4MB objects are deleted, and a new 4MB object is created.

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.

Additional Information

TR-4598: This percentage, the unreclaimed space threshold, can be customized, but is set to different default levels for different object stores.
  • The default unreclaimed space thresholds are:

• 14% IBM Cloud Object Storage
• 15% Microsoft Azure Blob Storage
• 20% Amazon S3
• 40% StorageGRID

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.