This v40z has an LSI 53C1030 SCSI Controller and I wanted to build a RAID1 array out of the two disks present. However, once in the configuration menu (press CTRL+C when the MPTBIOS is being initialized), it's impossible to add any disk to a RAID array:

 Adapter Properties → RAID Properties → 
 Select a disk and press +

Now the following choices appear:

       F3 – Keep Data (Create 2 disk array)
 Delete – Erase Disk (Create 2 to 6 disk array)

I didn't care for the data and pressed Delete to build a fresh array. But this didn't happen, instead the following was printed:

 Can't keep data. Incompatible partition.
 Press DELETE if data loss OK or any other key to cancel

The user guide even has entry for this, suggesting to remove any partitions of type 8e (Linux LVM) from the primary disk. Well, the disks in question had an operating system installed, not a single partition was of type 0x8e.

Anyway, I booted the system into a recovery, deleted all partitions and created just one single partition of type 0x83 (Linux). Again in the MPTBIOS and I still cannot create a RAID array, as the very same error message appeared. Grrr.

Back into recovery and to delete the single 0x83 partition created earlier. That did the trick, now MPTBIOS did not complain and the RAID array is now in place. Yay! :-)