When creating a disk-partitioned root aggregate, two key rules are automatically enforced. First, a RAID group cannot have more than one partition from the same disk. This ensures redundancy and fault tolerance by spreading data and parity across multiple physical disks. Second, the only supported RAID type for aggregates containing root-data partitioned disks is RAID-DP. RAID-DP provides double-parity protection, which is crucial for maintaining data integrity in the event of multiple disk failures.