You configure Data ONTAP to automatically assign disks at the stack or shelf level, depending on your system requirements and configuration. By default, autoassignment is at the stack or loop level. Data ONTAP automatically assigns the unowned disks to the system that owns the rest of the disks in that stack or loop.
If you need to have the disks in a single stack owned by more than one system, you can configure Data ONTAP to perform automatic disk assignment at the shelf level. In this case, Data ONTAP automatically assigns the unowned disks to the same owner as the already assigned disks on that shelf.