Hope this helps.
Is Local SyncMirror supported in Advanced Disk Partitioning (ADP)？
https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/Is_Local_SyncMirror_supported_in_Advanced_Disk_Partitioning_(ADP)%EF%BC%9F
Add a local tier (create an aggregate):
https://docs.netapp.com/us-en/ontap/disks-aggregates/add-local-tier-overview-task.html
Workflow to add a local tier (aggregate):
https://docs.netapp.com/us-en/ontap/disks-aggregates/aggregate-creation-workflow-concept.html
