You can transition the primary and secondary HA pairs that contain the volumes of a 7-Mode SnapMirror relationship in parallel. You must then manually set up the volume SnapMirror relationship in clustered Data ONTAP after transition. The SnapMirror relationship is retained after transition without requiring a rebaseline.
You must have prepared the source and destination clusters for transitioning the SnapMirror relationships.
Preparing the cluster for transitioning volume SnapMirror relationships