Long story, short: how can I boot from a USB key using the GRUB bootloader that Proxmox VE installs? (I'm running on an Apple Mac Mini)
More detailed version:
I installed Proxmox VE v8.1 on an old Apple Mac Mini a few months ago. I've since realised I don't need Proxmox, so I want to wipe the machine and reinstall Ubuntu on it instead. I have created a bootable Ubuntu (Server 24.04) installation USB. I have that plugged into the Mac Mini.
Upon boot, I should be able to press the option key to choose the boot device. However, that's for the Apple bootloader, which I gather Proxmox VE has replaced with GRUB.
So I need to be able to boot from the USB from GRUB instead. I don't know how to do this.
Upon booting the machine, I see the GRUB bootloader with various options for Proxmox, but of course no option for booting from the USB.
I found this article which explains how to point GRUB at the USB stick, but parts of those instructions aren't consistent with what I'm seeing, so I can't use those instructions directly. I gather from that article that I need to find an .EFI file that I point GRUB at, so it knows how to boot from the USB. Unfortunately, I'm struggling to find that .EFI file.
I have been able to open a command line (by pressing C in the GRUB menu). When I use ls to list the drives, I have (among others), hd0,msdos1 and hd0msdos2.
I gather this is different to a normal console (e.g. what I would see on a Debian system), because I can't, for instance, run pwd or cd, so I can't cd into a directory, etc. The find or even which commands don't work either. These commands don't seem to be installed on this system...(?)
In any case, I was able to set root=(hd0,msdos1) as per the article. Then I was able to enter:
chainloader / and then press tab, and that showed me a list of directories available.
If I do this with set root=(hd0,msdos1) and set root=(hd0,msdos2), I can see that for
set root=(hd0,msdos2)
chainloader /boot <tab to see sub-directories>
....there's nothing in there that I recognise, and certainly no EFI file.
Elsewhere on the internet I saw a suggestion it might be in /etc/default, but nope, can't see anything there.
How can I boot from a USB key using the GRUB bootloader that Proxmox VE installs?
Thanks in advance.
More detailed version:
I installed Proxmox VE v8.1 on an old Apple Mac Mini a few months ago. I've since realised I don't need Proxmox, so I want to wipe the machine and reinstall Ubuntu on it instead. I have created a bootable Ubuntu (Server 24.04) installation USB. I have that plugged into the Mac Mini.
Upon boot, I should be able to press the option key to choose the boot device. However, that's for the Apple bootloader, which I gather Proxmox VE has replaced with GRUB.
So I need to be able to boot from the USB from GRUB instead. I don't know how to do this.
Upon booting the machine, I see the GRUB bootloader with various options for Proxmox, but of course no option for booting from the USB.
I found this article which explains how to point GRUB at the USB stick, but parts of those instructions aren't consistent with what I'm seeing, so I can't use those instructions directly. I gather from that article that I need to find an .EFI file that I point GRUB at, so it knows how to boot from the USB. Unfortunately, I'm struggling to find that .EFI file.
I have been able to open a command line (by pressing C in the GRUB menu). When I use ls to list the drives, I have (among others), hd0,msdos1 and hd0msdos2.
I gather this is different to a normal console (e.g. what I would see on a Debian system), because I can't, for instance, run pwd or cd, so I can't cd into a directory, etc. The find or even which commands don't work either. These commands don't seem to be installed on this system...(?)
In any case, I was able to set root=(hd0,msdos1) as per the article. Then I was able to enter:
chainloader / and then press tab, and that showed me a list of directories available.
If I do this with set root=(hd0,msdos1) and set root=(hd0,msdos2), I can see that for
- msdos1: contains a bunch of files but no directories. Of interest are boot.scr, bootcode.bin, cmdline.txt... but I note there are no *.efi files.
- msdos2: contains the typical directories of a Debian-based system, e.g. boot/, dev/, etc/, home/ and so on.
set root=(hd0,msdos2)
chainloader /boot <tab to see sub-directories>
....there's nothing in there that I recognise, and certainly no EFI file.
Elsewhere on the internet I saw a suggestion it might be in /etc/default, but nope, can't see anything there.
How can I boot from a USB key using the GRUB bootloader that Proxmox VE installs?
Thanks in advance.
