I used end to end process to create a dataset with a Storage Service and I've been surprised to see that QSM uses the preferred IP addresses of storage systems rather than those of source and destination vFiler Units
Preferred IP addresses are set for each host (Storage systems and vFiler Units).
Each host uses its dedicated preferred IP address.
Storage Service uses a provisioning policy and a protection policy.
Provisioning service :
no guarantee space
Reserve space for snapshot
Protection policy :
base policy = Backup
Local backup schedule set on primary data
Backup retention duration set on primary data
Mirror schedule : once a day
Backup retention duration set on secondary data
vFiler Units are attached to Primary data and Backup.
During dataset creation OCUM assigns created volumes to corresponding vFilers
... and all storage objects are created.
However, in snapmirror.conf the IP addresses are those of hosting storage systems
According to our understanding of the KB on ocum management of relationships between vFilers (thanks to Kevin https://kb.netapp.com/support/index?page=content&id=3013156), we were supposing that ocum uses IP addresses available on physical storage systems and that it uses prefered IP addresses assigned to vFilers Units hosts in the same way it uses the physical storage systems ones.