You can perform a failback using a disaster recovery plan only if the destination volumes are resynchronized in the reverse direction to the original production storage resources. You can also create a new disaster recovery plan to fail over the Exchange storage resources to the production site.
Ensure you meet all the prerequisites mentioned in the document before you start the failback process.
By resynchronizing the destination volumes in the reverse direction, all the data is transferred from the original SnapMirror destination volume at the disaster recovery site, to the original SnapMirror source volume at the production site. SnapManager then initializes the destination volumes.
Perform a release operation on reverse mirrors after you fail back.