How do I install bootloader only?

Hi,

Here’s my use case:

I have a Proxmox host I’ve installed Windows as a guest VM and passed through a video card to use as my gaming/main working desktop PC.

I’m also passing through via PCIe a NVMe SSD, since the GPU needs to be passed through the guest needs to use a OVMF/UEFI BIOS.

Usually what happens when I boot is it’ll get stuck on not finding a CD/Network to boot off of and land me in the UEFI shell, at which point I can exit and boot from the NVMe SSD. Or I can bypass all that by hitting ESC when boot is starting.

I’ve tried changing the boot order in the UEFI BIOS for the guest but it seems like Proxmox rewrites those changes every time the guest boots. Worse than that, Proxmox does not have an option in its boot order settings to boot off NVMe SSD.

What I’ve been doing is putting in a GRUB rescue disk and manually selecting the boot option for the NVMe drive or just hitting ESC during boot and manually selecting it that way. This isn’t ideal.

So, I want to create a small vdisk (~10MB) for just GRUB, set Windows on the NVMe drive as the default option and just boot to it with a 1 second default timer.

Unfortunately I can’t find a guide for doing this anywhere dated recently (including the configuration of the Grub menu files) nor can I find a ISO with only grub on it, most grub documentation seems to be about repairing Ubuntu installs, does anyone know how to do this?

You can install grub from any livecd that has grub on it. I recommend the gentoo wiki’s page on installing grub.
https://wiki.gentoo.org/wiki/GRUB2#Installing_the_boot_loader

1 Like

I actually figured out a cleaner solution:

Create a second vdisk with 1GB (or less) storage
In Windows create a EFI partition on that vdisk through these instructions (https://www.anyrecover.com/hard-drive-recovery-data/how-to-create-and-delete-efi-system-partition-in-windows/)
In Windows, move over the EFI partition using EasyUEFI.
Set the second vdisk as boot disk.
Done!

I actually had problems with linux restore disks because for some reason they weren’t recognizing the graphics card. I had to use one which doesn’t use a GUI (system rescue CD), and it was still pretty confusing because the EFI partition is on the NVMe SSD, and obviously it’s not going to help things installing GRUB on the same NVMe SSD. Anyways, I’m glad the solution above worked.