Grub rescue Filesystem error solved

Unknown Filesystem Error – Grub Rescue Fix

This post will quickly show you how to solve unknown filesystem error when trying to boot an OS version from your machine.

Grub no such partition error
Grub rescue unknown filesystem
Grub rescue unknown filesystem

Why does this happen?

In my case, I have a dual boot that allows me to choose between Windows 10 and Manjaro Linux. I encountered this problem when I used Windows and it started doing updates and trying to restart to install them. It seems like Windows overwrites some files at some level and messes up both systems and the dual boot tool.

How to fix it?

You can fix this very simply and quickly with just a few commands. No need to reinstall your OS and lose any data because your data is still there, ready to be loaded.

Follow the commands below to fix the issue:

  1. You will be shown the grub rescue command line. Run set to check how your machine is set up to boot the OS.
  2. Run ls to see the names of the available partitions.
  3. Run ls (partition name) to check if it has got any booting file. Example: ls (hd0, msdos1)
  4. Run set root=(partition name) . Example: set root=(hd0,msdos1)
  5. Run set prefix=(partition name)/boot/grub . Example: set prefix=(hd0,msdos1)/boot/grub
  6. Run insmod normal
  7. Run normal
  8. This will restart your machine and take you to the dual boot screen to let you select your OS.
  9. Boot your linux system, open a terminal and run: sudo update-grub
  10. Then run sudo grub-install /dev/sda (sda might differ on yours)

In conclusion, this blog post shows you what commands to run to allow you to use grub rescue mode to fix your OS loading issue. Once you go through these steps you will be able to restart your machine and not see the ‘unknown filesystem’ error.

2 thoughts on “Unknown Filesystem Error – Grub Rescue Fix

  1. When I run “insmod normal” I get a “error: unknown filesystem.” error. Any idea how to fix that?
    Every “fix” I found recommends the same set/insmod/normal commands but they don’t work for me.
    I’m running linux in a virtual machine and probably messed something up when resizing a disk.

    1. Hey, if you’re just using a VM I’d suggest getting rid of it and installing a fresh version. For me just following the steps in this post solved the problem.

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