For a Data ONTAP system ordered with disk shelves, you are not required to set up the system to work with array LUNs during initial installation. In the case of a Data ONTAP system using only array LUNs, you need to assign only two array LUNs during initial installation.
If you ordered your Data ONTAP system with disk shelves, you do not need to assign any array LUNs initially because the factory installs the root volume on a disk for you. If you are using only array LUNs, you must configure one array LUN for the root volume and one array LUN as a spare for core dumps during initial installation. In either case, you can assign ownership of additional array LUNs to your system at any time after initial installation.
After you configure your system, you might assign ownership of an array LUN in the following circumstances: