On Sat, Mar 02, 2019 at 11:04:54PM +0100, info at smallinnovations dot nl wrote:
> On 02-03-19 23:02, Alessandro Selli wrote:
> > On Sat, 2 Mar 2019 at 16:06:51 -0500
> > Hendrik Boom <hendrik@???> wrote:
> >
> >> Currently booting from a 750G BIOS-partitioned disk.
> >> Trying to enable booting from the 4.7T drive, which is GPT
> >> partitioned.
> >>
> >> With grub-install I get errors:
> >>
> >> april:/farhome/hendrik# grub-install /dev/sda
> >> 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. april:/farhome/hendrik#
> >>
> >> Evidently there is some kind of incompatibility here.
> >>
> >> What is going on? What can I to do other than continuing to boot
> >> from small BIOS disks?
> > See if this helps you:
> >
> > https://askubuntu.com/questions/671809/grub-install-this-gpt-partition-label-contains-no-bios-boot-partition
> >
> > In short: you need to have a "BIOS boot partition" of any size to
> > make grub-install happy.
> >
> >
> > Alessandro
> > _______________________________________________
> > Dng mailing list
> > Dng@???
> > https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
>
> And according to
> https://superuser.com/questions/1337344/is-it-possible-to-boot-linux-from-a-gpt-disk-on-a-bios-system
> it should be the first and a 1M+ partition with BIOS boot partition type

I can't find where it says that, but I'll take ot for truth.
So on my system the question becomes -- does it have to be sda1, or does it
have to have the lowest disk address of the partitions on the disk?


april:/farhome/hendrik# fdisk -l /dev/sda
Disk /dev/sda: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: BE827DEE-CAB8-4DA0-9962-4EE20884A4AC

Device          Start        End    Sectors  Size Type
/dev/sda1     2099200    4196351    2097152    1G Linux filesystem
/dev/sda2  1077938176 5860532223 4782594048  2.2T Linux RAID
/dev/sda3     4196352    6293503    2097152    1G Linux RAID
/dev/sda4     6293504    6313983      20480   10M Linux filesystem

Partition table entries are not in disk order.
april:/farhome/hendrik#


I think my boot configuration uses uuid's to find partitions...
... but that is likely different for getting the zeroth sector boot
loader to find the boot loader elsewhere. Or is there room in the MBR to
indicate the absolute disk address of the boot partition?

I will guess that boot partition has to be on the same disk as the MBR.

And this boot partition that has to be at the "start", I suspect that isn't
the partition that remains mounted as /boot after the Linux system is up and running.

-- hendrik