Le 22/11/2018 à 21:24, Daniel Fishman a écrit :
I'd expect that Grub won't be able to reliably work with that setup - partition 3 goes past the 2TB mark, so the BIOS won't be able to map it properly. Don't forget, when grub is reading the disk all it can rely on are BIOS calls. Add yourself a small-ish /boot partition first and you may be OK.Thanks, indeed this was the problem - after adding a boot partition the HDD now boots on BIOS-only machines.
So these machines have a broken BIOS implementation.
Unfortunately, it does not boot on UEFI machines.
Of course not. EFI boot requires a FAT-formatted EFI partition and grub-efi-{amd64|ia32} depending on the firmware architecture (not the CPU).
If the EFI firmware can boot in legacy BIOS compatibility mode, it may require to set the boot flag on the protective GPT partition entry in the protective MBR. Use parted disk_set pmbr_boot or fdisk -t dos.