How does ONTAP's data deduplication help storage efficiency?

• A. Deduplication eliminates duplicate data blocks across volumes, reducing the amount of physical storage needed.
• B. Deduplication increases metadata overhead and reduces performance.
• C. Deduplication only affects network traffic.
• D. Deduplication is automatically enabled on all volumes.

Answer: (A)

Data deduplication works by identifying identical data blocks that appear in multiple places and storing only one copy of that data, while using metadata to reference that single copy wherever it’s needed. ONTAP uses pointers to that shared block, so duplicates don’t consume extra physical storage. The result is a smaller overall storage footprint, which is especially valuable for data with lots of repetition such as VM images, backups, or OS dumps. Typically you enable deduplication per volume, and while there is some metadata to track the references, the main benefit is the reduced capacity usage.