Description of problem:

Many recent motherboards, particularly those supporting UEFI also provide ability for the user to set up an OS independent RAID array controlled by the motherboard firmware. The partitioning of the member disks is non-standard and not recognised directly by any partitioners (except Gnome Disks). This includes Mageia. The installer comes up with a message "Partition table of sdx is too complex for me. Do you want to ...". Later on, the partitioner is willing to trash a member disk of this array.

Specifically, the first disk is not recognised and throws the above message.
The second disk is mistaken to be an MBR partitioned disk and can be damaged depending on options selected by the user and partiStioning proposals made later on.
Isw_ raid has been raised in other bugs, including MGA4 and earlier (eg 11105), and presumably will be fixed when a modernised partitioner is provided in the installer.

For now, mis-identification of disks in an evironment where there might be 4 disks on a machine (even a laptop) is dangerous.

Note this bug is not about operating-system defined and controlled software raid - only the motherboard firware variety.

Reproducible: 

Steps to Reproduce: