Thin provisioning enables you to allocate storage in a volume or LUN as it is needed instead of reserving it in advance. This reduces the amount of physical storage you need by allowing you to over-allocate your volumes or LUNs based on potential usage without reserving space that isn’t currently being used.

Deduplication reduces the amount of physical storage required for a volume in three distinct ways.

Deduplication is supported within volumes and across volumes within an aggregate. Reads of deduplicated data typically incur no performance charge.

Compression reduces the amount of physical storage required for a volume by combining data blocks in compression groups, each of which is stored as a single block. When a read or an overwrite request is received, only a small group of blocks is read, not the entire file. This process optimizes read and overwrite performance and enables greater scalability in the size of the files being compressed.

Compression can be run inline or postprocess. Inline compression provides immediate space savings by compressing data in memory before it is written to disk. Postprocess compression first writes the blocks to disk as uncompressed and then at a scheduled time compresses the data. You need to manually enable compression.

Compaction reduces the amount of physical storage required for a volume by taking data chunks that are stored in 4 KB blocks, but that are less than 4 KB in size, and combining them into a single block. Compaction takes place while data is still in memory so unnecessary space is never consumed on disks. It is enabled by default on ETERNUS AX/AC series and ASA systems. You need to manually enable compaction on ETERNUS HX series.

FlexClone technology leverages Snapshot metadata to create writable, point-in-time copies of a volume, file or LUN. Copies share data blocks with their parents, consuming no storage except what is required for metadata until changes are written to a copy or its parent. When a change is written, only the delta is stored.

Where traditional dataset copies can take minutes or even hours to create, FlexClone technology lets you copy even the largest datasets almost instantaneously.

ONTAP provides temperature-sensitive storage efficiency benefits by assessing how often your volume’s data is accessed and mapping that frequency to the degree of compression applied to that data. For cold data that is accessed infrequently, larger data blocks are compressed, and for hot data, which is accessed frequently and is overwritten more often, smaller data blocks are compressed, making the process more efficient.

Temperature-sensitive storage efficiency (TSSE) is introduced in ONTAP 9.8 and is enabled automatically on newly created thinly provisioned ETERNUS AX volumes.