Grub-install failure...

[Colin Watson]

On Fri, Feb 12, 2021 at 03:19:20PM -0500, Robert Heller wrote:
> Grub-install is failing:
> 
> sauron% sudo grub-install /dev/sda
> [sudo] password for heller: 
> Installing for i386-pc platform.
> grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
> grub-install: error: embedding is not possible, but this is required for RAID and LVM install.
[...]
> What am I missing? Grub 1 is happy and I can boot that way, but it is
> presently defaulting to CentOS 6.10. I am at this point ready to install grub
> 2 and make the default boot to be Ubuntu 18.04, but grub 2's installer is
> complaining... My motherboard's BIOS is an older one (not UEFI). When I
> installed these 2TB disks, I set asside a UEFI partition (part 1 on /dev/sda
> and /dev/sdb), but I am presently not using it -- I anticipate getting a new
> motherboard, which will likely have a UEFI boot prom.

I think your best bet then will be to change the types of /dev/sd[ab]1
to "BIOS Boot Partition" for now, thereby allowing them to be used to
store boot loader data, assuming they're empty as well as unused at the
moment.  It ought to be possible to remake that pair of partitions as
EFI System Partitions later.

https://www.gnu.org/software/grub/manual/grub/grub.html#GPT may be
helpful here.

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]