I wanted to update my findings and efforts on this situation in trying to make this work:
First, I have used Rufus 3.14 to write the most recent ISO (
TrueNAS-SCALE-21.06-BETA.1.iso) to USB both with MBR and GPT.
When I boot to a GPT USB 2 flash drive into the R710 with UEFI boot mode enabled with TrueNAS SCALE on it I get GRUB errors:
When I boot to an MBR USB 2 flash drive into BIOS boot mode enabled with TrueNAS SCALE on it, it starts up and the installation proceeds and I can install it to a drive installed on the system...
What I find particularly strange is that the system will NOT boot with BIOS boot mode still enabled after the installation completes. I then changed the system to UEFI boot mode again and tried to start the system. When I got to the UEFI boot selector the TrueNAS SCALE installation on the SSD on embedded SATA port A shows up... AND BOOTS.
This is very strange behavior and we need to isolate what is going on here. I think we need to come up with some more clear instructions and expectations since something is really screwy here.