Arch Linux

dynosaw

Member

Registered: 2018-07-12

Posts: 54

[Solved] Does grub-install with --removable option support dual boot?

This question concerns a stand-alone, domestic, desktop PC
running under Arch. All attempts so far to get Debian-11 to
'dual-boot' as a second linux opSys have failed. Debian simply
doesn't boot.

Background.
PC has an ASUS motherboard, Intel 64-bit chipset, UEFI firmware
with no legacy BIOS support. Arch was installed on a 500GB SSD
mounted directly on the motherboard. And it runs well.

The Debian opSys was installed onto a separate internal hard disk
/dev/sdb (not on the SSD) from the command-line using debootstrap.
The process was halted after vmlinuz and initrd.img had been installed.
I.e. there is no conflicting grub loader on the Debian hard disk.
The Debian addendum file to grub.cfg, /etc/grub.d/40_custom resides
on the Arch root partition (SSD) and grub-mkconfig was run under Arch.

On start-up, "Debian 11" appears in the grub boot menu; selecting
"Debian 11" produces a torrent of text on the monitor which suggests
that Debian's vmlinuz and initrd.img have been found. But then it
all stops with a blank screen and an inert keyboard.

The /boot arrangement is unconventional in that there is no
/boot/efi directory. After start-up the EFI (FAT-32) partition is
mounted directly to the /boot directory

In addition the grub-install for the original Arch installation
was run with the --removable option set.

Questions
All my previous dual boot installations on other machines were for
BIOS firmware, and UEFI is a strange world for me. Can anyone tell me,
please:
1.    Does installing grub-efi with the --removable option preclude
      a dual boot?
2.    Is the unorthodox /boot mounting point for the EFI partition
      a potential source of the trouble?

Any advice on how to continue trouble shooting is welcome.

Thanks in advance.
Dynosaw
--

Last edited by dynosaw (2022-06-01 14:45:07)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,285

Re: [Solved] Does grub-install with --removable option support dual boot?

Nothing about the --removable option has any inherent effect on any dual boot considerations, but it will logically change the handling a bit. The only thing the --removable option does is not create an NVRAM entry and instead populate the UEFI fallback path. The only thing affects is what your mainboard is booting, which should be that fallback path. Once you are in GRUB and GRUB is reading it's own configuration then whether or not you used --removable is entirely irrelevant.

so in regards to your first question, no it does not. For the second question generally this will not matter (... it might matter if you didn't have the ESP mounted during initial grub-install invocation but are retroactively doing so now, in which case the config you think you are updating and the config GRUB is actually reading might diverge, and of course, making sure you actually have sufficient free space to hold all the images/initramfs you might have on there), but we'd need to know what exactly you are booting how and where, so I suggest you post your /boot/grub/grub.cfg in code tags

From what you are describing this sounds plainly like an issue in your debian installation and you might have to ask on boards more equipped to help with that.

PS: The forum has pretty useful autowrapping, while structuring the text into paragraphs makes sense, doing explicit line breaks at seemingly arbitrary junctions reads quite jarring on larger screens, consider not doing that for single paragraphs

Last edited by V1del (2022-06-01 14:41:18)