Qtree SnapMirror or SnapVault source transfers some unchanged blocks after deduplication

If qtree SnapMirror or SnapVault updates occur before deduplication completes on the source volume, then in addition to actual changed blocks, the source might also transfer some unchanged blocks to destination during the next update.

If deduplication is not running on the destination volume, then the redundant data transferred occupies more storage on the destination volume.

Before you enable deduplication on the source volume, it is recommended that you follow these best practices:

Ensure that deduplication is run on qtree SnapMirror or SnapVault destination volume if deduplication is running on the source volume.
Schedule the update transfers in such a way that these transfers are run only after deduplication on the source volume finishes.

For more information, see the SnapVault Best Practices Guide.