I resolved the problem with a combination of one of the actions: I tried Redhat 8.6 and updated BIOS to latest available on the Dell site.  
I'm trying to build an old PowerEdge R715 server with Redhat 8. I tried 8.1 and 8.3 DVDs: both tell me there are no disks. Redhat 7.9 sees the disks. BIOS is currently at 3.2.2 and I just updated the H700 controller firmware to 12.10.7. Is there a driver available?  I looked in various places online and also at [URL] Thanks!!  
Need Redhat 8 controller drivers for old R715, H700 controller