On Wed, Jun 07, 2017 at 03:27:30PM -0400, Haines Brown wrote:
> The problem was more worked around than resolved.
>
> After having no grub modules with an installation on a new disk, whether
> DVD or netinst ISO, I knew the problem wasn't with the disk. I installed
> Devuan Jessie more or less successfully on a new disk without the old
> disk being connected. Then I reconnected the old disk and now can boot
> either operating system successfully.
>
> If anyone has an idea of what might be the problem, I'd appreciate
> knowing. Perhaps with both disks attached, the presence of one
> preoccupies the SATA port needed by the other.
>
> Incidentally, the key on which the ISO is installed names itself UEFI. I
> have both UEFI and legacy selected in BIOS. If I have just legacy,
> nothing boots.

This brings up a related issue.

I have a machine with both old-style MBR (fdisk) partitioned and
gpt-style (needs gdisk) partitioned disks. It boots using grub or
lilo.

Grub from a boot record on an MBR-partitioned disk and LILO from a
boot record on a floppy drive. (I have lots of backup boot floppies
in case one goes wrong)

In either case, /boot and / are on software RAID partitions on the
GPT drives.

The GPT drives have to be GPT drives because they are large. The MBR
drives are legacy drives from the old days.

How would booting from the GPT drives work? It's an old machine whose
BIOS looks for an MBR. I may well be forced to do this is my legacy
disk drives fail.

If I were to transplant my GPT-formatted drives into a modern machine
that expects an EFI boot, would it just work? Or would I have to do
something major -- like repartition -- that puts my data at risk?

-- hendrik