1 Download RAID Driver for Red Hat Enterprise from Fujitsu Support site.
2 Save the driver ISO Image into a USB drive.
Create a RAID Volume using The bios Utility.
At Centos installation prompt, press E to edit 'Install Centos 7' linuxefi line.
Add the following text at the end of the line: inst.dd modprobe.blacklist=ahci.
You will be asked to choose the drive with the driver iso image; choose the driver and press ctrl X to confirm your selection; Continue installation, your raid volume should be detected.