- Cloud Volume ONTAP (CVO)
- Amazon Web Services (AWS)
- Fabric Pool
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.
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.
This percentage, the unreclaimed space threshold, can be customized, the default settings are 20% for Amazon S3.