unknown filesystem, grub rescue

Question

When I try to boot I get this message:

error: unknown filesystem.
grub rescue> _

results of:

grub rescue> ls

are as follows:

(hd0) (hd0,msdos5) (hd0,msdos1) (hd1) (fd0)

Solution 1

If you don't know your Ubuntu boot partition, check them one by one:

ls (hd0,msdos5)/
ls (hd0,msdos1)/

When you hit the right one, you'll get a line mentioning "lost+found" and so on.

Assuming (hd0,msdos5) is the right partition:

set root=(hd0,msdos5)
set prefix=(hd0,msdos5)/boot/grub
insmod normal
normal

Now you'll be able to boot into Ubuntu. Once you do, reinstall GRUB:

sudo update-grub
sudo grub-install /dev/sda

Solution 2

If you have a UEFI bios make sure you boot through uefi boot and not legacy. Grub is actually there but the bios doesn't allow it to start

Solution 3

The easiest way i found to fix this error was to put in an old windows 98 disk and in dos you can delete and create partitions and then format

Comments

[user2014111]

Hey I am having the same problem as you had of grub rescue how did you fixed it? can you explain me.

[Chandler R.]

Honestly, user2014111, I actually had to copy the files off of the HDD, and then I re-installed the whole OS. Sorry I couldn't be of more help... -Chandler

[karel]

Possible duplicate of Grub rescue - error: unknown filesystem

[Chandler R.]

Nevermind that. I got it fixed! Thank you so much!

[Pavel]

Ur wlcm. Plz mark as answered.

[Ekaveera Gouribhatla]

Hi Chadler..i am getting file not found error when i type insmod normal. please help me

[Chandler R.]

Hey, sorry for the late response, I have not been on StackExchange in months. You, Ekaveera, may already have it fixed, but if not, I can try to help you. However, I had the same error. I believe those instructions are for an outdated version of Ubuntu. Easiest fix is to wipe the OS and then re-install. -Chandler

[travelingbones]

I show (hd0), (hd0,1), ... None show an msdos and running ls (hd0,n) for each n produces error: unknown filesystem. any ideas?