Deduplication works at the block level on the active file system, and uses the WAFL block-sharing mechanism. Each block of data has a digital signature that is compared with all other signatures in a data volume. If an exact block match exists, the duplicate block is discarded and its disk space is reclaimed.
You can configure deduplication operations to run automatically or on a schedule. You can deduplicate new and existing data, or only new data, on a
FlexVol volume.
Deduplication removes data redundancies, as shown in the following illustration: