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?