ZFS send dedup integrated in Opensolaris
A few days deduplication for ZFS pools found it’s integration to Opensolaris. Now the in-stream deduplication feature for ZFS send streams has followed the on-disk variant. With this feature blocks are just transmitted once in a stream, thus the depending on the data you have to transmit less data, as the ZFS just sends a reference to an already transmitted block instead the full data. You will find further information in the case log for PSARC 2009/557.