I found a workaround and was able to install UCS. I am not 100% sure what the problem was but it clearly comes from the ISO file since I was able to install Debian and Ubuntu. Most likely, the issue is because this mini-computer can only boot in UFI mode and is not able to simulate the old BIOS mode. However, it appears that the UCS ISO might not be properly configured to load in UFI mode. They might have included the wrong version of the bootloader GRUB2. Fortunately, most large computer firmwares are designed to simulate the BIOS mode and can install UCS in this old mode.
Here is the solution I found:
First, check that GRUB2 has a problem seeing all the drives. For that try to boot and when you get to the GRUB shell, type ls if all you get is
GRUB>ls
(proc)
then the start from step 1
if you get something like
GRUB>ls
(proc), (hd0), (hd0,gpot1), (hd1)
go directly to step 2
STEP1:
- Burn the UCS ISO on a USB stick.
- Download a Debian distribution ISO and mount it as a drive (or burn it to a USB stick).
- Copy the file EFI/boot/grubx64.efi from the Debian ISO to EFI/boot/ on the USC ISO
- Erase the file EFI/boot/grub.efi on the USC ISO
- Change the name of EFI/boot/grubx64.efi to EFI/boot/grub.efi
Boot the computer from the UCS ISO stick. It will still go to the GRUB shell but now GRUB should see all the drives on the computer
STEP2:
You need to identify the partition containing your installation data.
At the GRUB prompt type ls, you will see the list of available drives/partitions.
GRUB>ls
(proc), (hd0), (hd0,gpt1), (hd1), (hd1, gpt1)
(hd0) is a drive, (hd0,gpt1) is a partition
type ls (x,y) -a where (x,y) is each of the partition until you see the one containing the installation data (You should see a file named .univention_install)
then type the following:
GRUB>set root=(x,y)
GRUB>linux /install.amd/vmlinuz
GRUB>initrd /install.amd/initrd.gz
GRUB boot
… and the computer should be booting on the installation drive.
