System needs to be at BIOS 2.x revision. If you have 1.x, then your IOMMU setting needs to be enabled, and then prompt the Marvell 9230 RAID Controller during POST (I think the prompt is ctrl+r).

In BIOS setting

RAID1, no other option.

How it appears in Ubuntu 20.04 OS installation

Shows up as SMC VD

Partition as usual