NetApp Volume Encryption (NVE) is a software-based data-at-rest encryption solution that secures data on a per-volume basis using individual, unique data encryption keys (DEKs) for each FlexVol or FlexGroup volume. Because NVE performs cryptographic operations at the volume layer within the WAFL stack, storage efficiency features operate differently depending on whether they function at the volume layer or the aggregate layer:

Data Compaction (Statement C): Compaction bundles multiple small, sub-4KB data chunks into a single physical 4KB block before encryption occurs within the volume, making it supported with NVE.

Volume Deduplication (Statement D): Inline and background volume-level deduplication identifies duplicate 4KB blocks within the boundaries of the specific volume prior to NVE encryption, preserving space savings.

Conversely, aggregate-level efficiencies—specifically cross-volume inline deduplication (Statement A) and background aggregate deduplication (Statement B)—require blocks across different volumes to be compared and shared within the aggregate. Because each NVE volume encrypts its blocks with an independent key, identical plain-text data produces distinct cipher-text across volumes, preventing cross-volume deduplication. To enable aggregate-level deduplication across encrypted volumes, NetApp Aggregate Encryption (NAE) must be utilized instead of NVE.