ONTAP Recipes: Did you know you can...?
Use ONTAP Storage Efficiency features to get maximum storage efficiency for AFF
Storage efficiency is the ability to store and manage data while consuming the least amount of space on disk with little or no impact on performance, resulting in a lower overall cost. Efficiency is not just about making the most of the physical blocks on the disk, it's also about being able to easily provision flexible storage.
All ONTAP Storage Efficiency features are supported on All Flash FAS, including:
- Thin provisioning: storage space is dynamically allocated to each volume or LUN as data is written.
- Compression: reduces the physical capacity that is required to store data on the storage system by compressing data chunks.
- Deduplication: eliminates extra copies of same data by saving just one copy of the data and replacing the other copies with pointers that lead back to the original copy.
- Compaction: reduction of storage of data without loss of information by eliminating unnecessary redundancy.
Features enabled on the volume can be viewed and modified using the volume efficiency config command.
volume efficiency config –volume $VOL_NAME –vserver $SVM_NAME
Thin provisioning is enabled by default (space-guarantee will be none)
volume show -vserver $SVM_NAME -volume $VOL_NAME -fields space-guarantee
About Storage Efficiency
Two modes of operation support flexible volume deduplication, compression and data compaction:
- Inline Storage Efficiency
- Background (i.e. Post-process) Storage Efficiency
Inline Storage Efficiency
The storage efficiency savings are achieved before the data is written to disk. This also includes cross volume deduplication. All inline efficiency features are enabled by default on newly created or existing flexible volumes of an AFF system. They can be explicitly assigned later by attaching an "inline-only" policy.
To explicity assign an inline policy:
vol efficiency config -volume $VOL_NAME -vserver $SVM_NAME -policy inline-only
Specific Inline features can be enabled by using corresponding fields in above CLI.
Background (i.e. Post-process) Storage Efficiency
The storage efficiency savings are achieved after the data is written to disk. Process can be run by issuing manual commands or setting volume efficiency policies based on schedule or threshold.This is by default disabled on AFF and can be enabled on a volume by attaching a policy/schedule.
To get deduplication, compression and compaction savings on the data written after recent efficiency operation:
volume efficiency start -volume $VOL_NAME -vserver $SVM_NAME dedupe true compression true compaction true
To achieve efficiency savings on old data in the volume:
volume efficiency start -volume $VOL_NAME -vserver $SVM_NAME -scan-old-data true dedupe true compression true compaction true
For background deduplication, a system created policy called "dafault" runs everyday at 12:00AM. To create a custom policy with a different schedule:
volume efficiency modify -vserver $SVM_NAME -volume $VOL_NAME -policy $POLICY_NAME
To enable both inline and background storage efficiencies on a volume which has an "inline-only" policy:
volume efficiency modify -vserver $SVM_NAME -volume $VOL_NAME -policy default
volume efficiency modify -volume $VOL_NAME -inline-dedupe true
-cross-volume-inline-dedupe true -compression true -inline-compression true -data-compaction true