In an attempt to get MaaS/OpenStack working with a x3650 M2 (7947), one of the big showstoppers we ran into was with the RAID controller not wanting to allow the disks to be seen as physical disks. This is something which the OpenStack installer wants to see, so we had to figure out how to turn it off. First we had to update the firmware of the RAID controller so that it would show up in UEFI (See the previous blog post on how to do that). Next we booted into the UEFI config by hitting
Now we have deleted all drives from RAID we need to now setup the drives as JBOD (just a bunch of disks). In order to do this, we created a bootable FreeBSD image by downloading the latest 64 bit UEFI FreeBSD image file (at the time this was FreeBSD-10.1-RELEASE-amd64-uefi-memstick.img, which can be found at https://www.freebsd.org/where.html). We then applied the downloaded image to a spare USB using Win32 Disk Imager. From there you can boot from the USB and when prompted choose the Live CD option. You will be given a shell prompt asking for a username and password. The username is root with no password. Once you are in you will need to run the following commands (commands courtesy of FreeNas forums).
mfiutil show drives
mfiutil create jbod NUMBER
For each number given by the first command, run the second command with that number as the parameter. Once you reboot all drives should then show up as disks to whatever operating system you install.