On 2020-08-03 05:56, John Pierce wrote: > Legacy BIOS has its own set of issues, like no GPT support, MBR disks > are > max 2TB. I'm booting just fine on an old BIOS system from a pair (mdraid 1) of 3 TB GPT disks. The MBR compatibility on GPT disks allow the old machine to boot from a GPT disk and load GRUB. Then GRUB takes over and loads the kernel and the kernel has no problems understanding GPT disks. The boot disks must have an EFI boot partition even though it's not used in this case. -- <(*) Jyrki