Having a server grade motherboard has its downsides as well, more specifically, getting the thing to boot from an installation disk when it just won’t use your DVD drive at all…
Luckily, good things come to those who search relentlessly!
In this case, it comes in the form of a FAQ entry. Just in case it may move and I need it again, here’s what what:
Please keep dvd-drive connect to SATA 5 or 6. Change following BIOS setting: Advanced --> PCIe/PCI/PnP configuration --> Launch Storage OpROM policy --> Legacy only Advanced --> Chipset configuration --> Integrated IO configuration --> Detect Non-compliance device --> enable Advanced --> Boot feature --> INT19 Trap response --> Postponed