How does data deduplication work in ONTAP?

• A. Deduplication eliminates duplicate data blocks to reduce storage usage, typically applied at the volume level.
• B. Deduplication increases performance by caching blocks in memory.
• C. Deduplication compresses all data globally across the cluster.
• D. Deduplication duplicates blocks to ensure data availability.

Answer: (A)

Deduplication in ONTAP works by identifying identical data blocks within a volume and storing only one copy of each unique block, with duplicate blocks replaced by references to that single copy. This reduces the capacity used to store data because multiple instances of the same blocks don’t occupy extra space. In ONTAP, deduplication is typically configured at the volume level, so each volume can manage its own dedup process. It’s not a caching mechanism, nor a global cluster compression, and it doesn’t duplicate data for availability—the goal is to save storage space by removing duplicate blocks.