Deduplication with volume SnapMirror

Starting with Data ONTAP 7.3 and onward, the deduplication metadata for a volume is placed outside the volume, at the aggregate level. This can improve the space savings achieved through the use of deduplication.

When replicating data using volume SnapMirror, the deduplication metadata for the volume is not replicated along with the volume. The data in the volume is usable both on the source and the destination.

To achieve maximum space savings on the destination volume, scan the entire file system to recreate the deduplication metadata for the destination volume. Use the sis start -s command to do so.

Note: The destination volume is accessible for read-write operations when the deduplication scan is in progress.

If you use the sis start command, without the -s option, the potential for space savings on the destination volume is reduced because only the new data written to the volume will be scanned for deduplication.