The array LUN used for the root volume must be larger than the minimum size required for other array LUNs. When planning for your root volume, you need to determine the minimum root volume size for the Data ONTAP release that is running on your system.
It is strongly recommended that you do not set the size of a root volume below the minimum size array LUN for the root volume that is shown in the Hardware Universe. The reason is that you want to ensure that there is sufficient space in the root volume for system files, log files, and core files. You need to provide these files to technical support if a system problem occurs.