Unable to install GRUB on iMac (2012)

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mcleaver
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Unable to install GRUB on iMac (2012)

Post by mcleaver »

Hi there.

Installing Mint 20.2 from a USB stick on a clean iMac with 512 GB SSD seemed to go wonderfully and very rapidly. It booted to the USB, and installing Mint was rapid and apparently successful - right up to the end, when it stopped with:
  • "Unable to install GRUB in /dev/sda
    Executing 'grub-install /dev/sda' failed'
    This is a fatal error.

I have since tried everything suggested (on the Telegram channel) but no luck.
Is it something to do with the iMac bios (of it has one) or a known issue? Can I manually install GRUB?
Regards
Martin
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
mcleaver
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Re: Unable to install GRUB on iMac (2012)

Post by mcleaver »

The installer seems to be moody. Yesterday I couldn't quite finish the etch with etcher. And then the installation stranded at the end without GRUB. Today both worked, but Mint did crash when I tried to start Firefox. I think it might have something to do with updates (NVidia?)
dorsetUK
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Re: Unable to install GRUB on iMac (2012)

Post by dorsetUK »

cleaver wrote: Thu Oct 21, 2021 11:18 am The installer seems to be moody. Yesterday I couldn't quite finish the etch with etcher. And then the installation stranded at the end without GRUB. Today both worked, but Mint did crash when I tried to start Firefox. I think it might have something to do with updates (NVidia?)
Hi cleaver and welcome to the forum.

As you seem to be able to boot into Mint, to be in a position to help you we need to know the details of your computer.

The easiest way to do this is for you to open your Terminal and paste

Code: Select all

inxi -Fxpmrz
into it and then hit Enter/Return.

Go to Edit, Select All, and then Copy, come back here, click on the code tags, </>, and then paste, Ctrl V.

With that, someone may be able to help.

HTH.
Reddog1
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Re: Unable to install GRUB on iMac (2012)

Post by Reddog1 »

Are you positive that your Mint installer made an EFI partition at the beginning of your hard drive? I'm assuming you have installed EFI with a GUID partition table, because Macs really don't work with MBR. That first partition should be roughly 200-500mb and be formatted FAT and be labeled 'EFI'. It is your /boot/efi partition, will be sda1, and is what GRUB is looking for. You can check by booting with your usb Live and opening the Disks app.

Edit: Since you seem to have the GRUB problem worked out, I'm actually surprised that Mint 20 even works with that old machine. And, a note on MBR and Macs. Those old Macs, the intel ones, had an emulated MBR mode, not a 'real' MBR. This was done because of Windows dual-boot and Windows lacked an EFI mode. That emulated MBR causes problems with Linux installs and leads to instabilities and crashes if Linux is installed any way but EFI.
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