[CentOS] Trying To Move From CentOS 6.10 To CentOS 7.5

I have this machine running CentOS 6.10 x86_64 and it's ripe to be moved 
to CentOS 7.5.

I mounted the DVD and rebooted and went through the graphic install 
until I reached the point of allocating the disks. It showed no 
available disk drives. There are 6 disk drives on this machine: 4 - 1 TB 
and 2 - 2 TB all WD Black - they have been made up with /dev/sda1 (1024 
MB) and /dev/sdd1 (1024 MB) as /dev/md0 (software RAID-1); with the 
remainder as software RAID-10 using LVM. The machine has the following 
allocations:

     /boot = /dev/md0 software RAID-1

    /dev/md1 as /dev/vg_jpdsys3 totaling 2.72 TB  software RAID-10.

Why can't the CentOS 7 installer see a CentOS 6 definition? Out of all 
of the LVS built I would only need to format the file systems the apply 
to the OS and swap. If I have to rebuild I will loose everything!  Any 
suggestions?

-- 
Eugene Poole
Woodstock, Georgia