Data deduplication is a method for eliminating redundant data in order to reduce the storage that is required to retain the data. Only one instance of the data is retained in a deduplicated storage pool. Other instances of the same data are replaced with a pointer to the retained instance.
Deduplicated data must be stored in sequential-access disk (FILE) primary, copy, and active-data storage pools that you enable for data deduplication. Because you can store more data on disk than on tape, data deduplication can reduce the overall amount of time that is required to retrieve data.