GRUB: EFI variables ar not supported on this device

Flotec09 · 2024-06-03 07:38:05

So my situation is the following;

I have a 1TB disk, which is divided up into 4 Partitons and already has Linux mint installed:

/dev/sdb1 : A small storage partionion for Windows, which is installed on another Disk
/dev/sdb2: My EFI partition
/dev/sdb3: The Linux Mint partition
/dev/sdb4: The Partition I made and formatted for Arch

So I installed Arch with the official installation instructions. But when I came to the point of installing the Boot manager, I had some problems.
I already have GRUB for switching between the Windows and Mint installation and I want to add an Entry for my Arch install.

I firstly mounted my EFI partition to my /boot/efi folder:

mount --mkdir /dev/sdb2 /boot/efi

Then I wanted to install GRUB with:

grub-install --target=x86_64-efi --efi-directory=/boot/efi

But it returned:

Installing for x86_64-efi platform
EFI variables are not supported on this system.
EFI variables are not supported on this system.
grub-install: error: efibootmgr failed to registry the boot entry: No such file or directory.

I think that my Motherboard is BIOS instead of UEFI.
How can I fix this?

Last edited by Flotec09 (2024-06-03 07:42:37)

Nikolai5 · 2024-06-03 08:14:53

On Mint or Arch live, run this:

cat /sys/firmware/efi/fw_platform_size

If it complains it doesn't exist, you're running BIOS, if it does exist you'll likely get 64 or 32 returned, in which case you are indeed running EFI.

What's the output of fdisk -l ?

Try mounting /boot instead of /boot/efi

Flotec09 · 2024-06-03 08:43:05

Hi! Thank you for the quick reply!

I already tried the

cat /sys/firmware/efi/fw_platform_size

command. It complained "File not found". So I am running a BIOS system.

And because I am currently at School and therefore can't test my PC at home, I will paste the exact output of

fdisk -l

in the evening. But as far as I remember from yesterday, it returned 4 Partitions on my Linux-Disk, like I described in my original question. And for the other Disks, I don't know, so I am going to check in the evening...

And I also tried mounting to /boot. Made no difference...

Last edited by Flotec09 (2024-06-03 08:45:08)

Nikolai5 · 2024-06-03 08:53:40

In that case follow the GRUB instructions for BIOS systems and see how you get on: https://wiki.archlinux.org/title/GRUB#BIOS_systems
The command you're using at the moment is specifically for EFI.

Do please post the fdisk -l when possible, just want to check what your sdb2 partition looks like, I would expect it to not be an efi type.

Arch Linux

#1 2024-06-03 07:38:05

GRUB: EFI variables ar not supported on this device

#2 2024-06-03 08:14:53

Re: GRUB: EFI variables ar not supported on this device

#3 2024-06-03 08:43:05

Re: GRUB: EFI variables ar not supported on this device

#4 2024-06-03 08:53:40

Re: GRUB: EFI variables ar not supported on this device

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