GRUB errors interfering with fresh fedora installation. ../grub-core/kern/...:unknown filesystem

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Hi all,
I’ve been using Fedora for 2 years. Currently on F39+Gnome. accumulated quite a lot of packages or unnecessary stuff, and wanted to upgrade to F40 with fresh installation.

My system is not starting with installation process after connecting Live Image USB because of grub issues, I guess.

Story:
I created F40 live image in USB stick using Fedora Media Writer. tried to boot up with the installation process but it threw me ERROR Verification failed: (0x1A) Security Violation with blue screen and kept giving me MOK menu. after some internet research I disabled secure boot.

now when I attach live image USB, it throws me to grub screen.
when I explore the directory, below is what I get:
notable error== error: ../ ../grub-core/kern/fs.c:121:unknown filesystem.
hd0 is Live F40 Image on USB
hd1 is local Fedora 39 and other partitions

grub> ls
(proc) (hd0) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) (hd1) (hd1,gpt4) (hd1,gpt3) (hd1,gpt2) (hd1,gpt1)
grub> ls (proc)/
luks_script
grub> ls (hd0)/
./ …/ boot/ EFI/ Fedora-Legal-README.txt images/ LICENSE LiveOS/
grub> ls (hd0,gpt3)/
error: …/ …/grub-core/kern/fs.c:121:unknown filesystem.
grub> ls (hd0,gpt2)/
efi/
grub> ls (hd0,gpt1)/
./ …/ boot/ EFI/ Fedora-Legal-README.txt images/ LICENSE LiveOS/
grub> ls (hd1)/
error: …/ …/grub-core/kern/fs.c:121:unknown filesystem.
grub> ls (hd1,gpt4)/
home/ root/
grub> ls (hd1,gpt3)/
error: …/ …/grub-core/kern/fs.c:121:unknown filesystem.
grub> ls (hd1,gpt2)/
efi/ System/ mach_kernel
grub> ls (hd1,gpt1)/
efi/ System/ mach_kernel
grub>

I tried resetting and reinstalling the grub as per Fedora docs for UEFI systems. tried Resetting and reinstalling GRUB 2 as per Fedora docs Working with the GRUB 2 Boot Loader. nothing has worked.

throughout this all, Fedora 39 is still working and accessible when I disconnect the Live Image USB stick. it boots to F39 normally.
but for some time it kept giving me that security violation error and MOK menu before I disabled secure boot. I’m assuming connecting the Live Image USB triggered something in local system.

Now, I don’t know how to go beyond that. internet has many examples of fixing grub by using Live boot image. but my system is not booting up with Live Image at all.

Thanks for any kind of help.

2

Are you a windows user?

3

The SBAT update should not affect Fedora as Fedora shipped and installed a fixed grub 2 years ago.

And f39 boots which shows grub is working.

4

This appears it may be an issue with the usb image.

You stated that you used fedora media writer to create the usb.
What has always worked for me when booted to fedora is to

  1. download the iso image to my hard drive.
  2. verify that image using the checksum file provided from the download page.
  3. attach my usb device and then make certain all partitions that may have been auto-mounted are no longer mounted.
  4. copy the iso image directly to the usb device using dd.
    a. From within the same directory where the iso image is located identify the usb device name. It may be /dev/sdb or similar.
    b. perform the copy.
    sudo dd if=Fedora-Workstation-Live-x86_64-40-1.14.iso of=/dev/sdb bs=64M
    The output file name (of=) should be the device name you identified earlier.
    The input file name (if=) should be the exact name of the iso image you downloaded(including path if necessary).

This should give you a bootable usb device that does not depend in any way whether secure boot is enabled or not, and is a hybrid boot image so you will either need to have bios set to uefi only or use the bios boot menu (F10, F11, or F12 on most machines) to select booting that usb device in uefi mode. The default boot mode is legacy on most systems when CSM is enabled and you do not specifically select to use uefi.

Attaching that usb device when booted to windows may cause it to fail the verification should you choose that option when booting.

EDIT
You can replace step 4 (and use of dd) by using the media writer and selecting the source as the file you downloaded. That eliminates waiting for the download while the device is being written to.

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5

No. no Dual Booting. I removed windows completely.

6

thanks for pointing out GRUB is not the issue here. I have no idea why it was giving that error: ../ ../grub-core/kern/fs.c:121:unknown filesystem..
I still think some minor issues were there in grub config files.

I prepared the boot drive one more time using terminal & dd as you suggested. BIOS was still not recognizing Live image in USB. i manually had to add USB as boot option and change priority as first boot option.

I finally got Live Image as boot option through GRUB menu afterwards. just now finished installing F40.

Thank you!!

1 Like