What is the minimum number of disks in a non-root aggregate with RAID-DP?

Two disks cannot satisfy RAID-DP's requirement for two dedicated parity disks plus at least one data disk.

RAID-DP uses a double-parity scheme with one row parity disk and one diagonal parity disk, requiring a minimum of two parity disks. Adding the required one data disk brings the absolute minimum disk count in a non-root RAID-DP aggregate to three disks total.

Five disks exceeds the minimum and reflects a common default or recommended group size, not the absolute minimum.

Eight disks is a larger group size sometimes used for performance but is not the minimum requirement.

Twelve disks is a typical default RAID group size in ONTAP but far exceeds the minimum of three.