Because qtree SnapMirror operates at the logical level, when data compression is enabled on the source storage system, the data is uncompressed in memory before being replicated to the destination system. If data compression is enabled on the secondary storage system, then all transfers are compressed on the secondary storage system.
You can use data compression to compress any existing data on the secondary storage system.
When using qtree SnapMirror with data compression, consider the following guidelines:
Therefore, no network bandwidth savings are achieved by data compression.
Therefore, space savings are achieved on the destination storage system.
When data compression is complete, all the newly compressed blocks are written as new blocks and all the newly compressed data blocks are transferred in the next incremental transfer.
For more information about qtree SnapMirror, see the Data ONTAP Data Protection Online Backup and Recovery Guide for 7-Mode.