The snapmirror resync command enables you to reestablish a broken SnapMirror relationship without a lengthy baseline transfer.
Resynchronization causes the loss of all data written to the destination after the base Snapshot copy was made. The snapmirror resync command informs you what data might be lost during the resynchronization and requests permission to proceed. If you want to save the data on the destination, you can stop the resynchronization, manually copy the desired data elsewhere, and reissue the snapmirror resync command to the destination.