Grub rescue> ls [partition] outputs "Filesystem is unknown" for all partitions. Shall I update/install(?) grub from live boot?

4 respostas [Última entrada]
Staircase
Desconectado
Joined: 02/24/2022

Hello,

When I start my computer, I land on this screen:


error: unknown filesystem.
Entering rescue mode...
grub rescue>

Based on what I read online, I should first try to find on which partition GNU/Linux is installed but I get "Filesystem is unknown" for all:


grub rescue> ls
(hd0) (hd0,msdos5) (hd0,msdos1)
grub rescue> ls (hd0)
(hd0): Filesystem is unknown
grub rescue> ls (hd0,msdos5)
(hd0,msdos5): Filesystem is unknown
grub rescue> ls (hd0,msdos1)
(hd0,msdos1): Filesystem is unknown

(I also tried adding "/" after ")" e.g. "ls (hd0,msdos5))

I went back online and found that if grub does not find a system on any of the partition, I should boot from a live boot and update(?) or reinstall(?) or do something to fix grub from the terminal; but I am not sure what command(s) to run, and if I should do that at all. I found suggestions which I don't want to risk trying.

Could someone confirm what commands I should run, if that is the right next step, or advise on a next step? Thank you.

---

Also, fyi, because I could not get anywhere via the grub screen, I booted my computer with GNU/Linux Trisquel 10 from a USB stick.

In Trisquel's menu, I can see the drive from which I would like to boot Trisquel from: "Trisquel's menu > Places > 127GB Encrypted".

When I click on "127GB Encrypted" and enter the password, an error message pops up: "Error Unable to mount 127 GB Encrypted Operation was cancelled". However - when I now go to Trisquel's menu I can see two partitions of this drive: "104 GB Volume" and "20 GB Volume".

When I click on "104 GB Volume", I can access my user folder, and from there, access all the folders (except "Mail"; there is a permission issue apparently).

Still from the live Trisquel session, I ran "SMART Data & Self-Tests" on all partitions. All "Overall Assessment" show "Disk is OK".

From the grub screen, I had also tried this with partitions 1 and 5, in vain:


grub rescue> set root=(hd0,1)
grub rescue> set prefix=(hd0,1)/boot/grub
grub rescue> insmod normal
error: unknown filesystem.

Geshmy
Desconectado
Joined: 04/23/2015

Well good luck.
Are you dual booting with Windows?
What did you do before the error started?

From: https://www.diskpart.com/articles/grub-rescue-unknown-file-system-0825.html "The reason for this error can be that you performed abnormal deletion of a partition where second/dual OS is installed. For example, this could be a PC where you were dual booting between Windows and Linux. However, you deleted the Linux partition."

From https://askubuntu.com/questions/142300/how-to-fix-error-unknown-filesystem-grub-rescue " "The answer below is meant for Ubuntu users who have just updated/recovered/reinstalled/installed OS X"

One case is for attempting a dual boot with Windows and the other is attempting to dual boot with OS X. But what's your case?

Staircase
Desconectado
Joined: 02/24/2022

Thanks for the response, Geshmy.

> Are you dual booting with Windows?

No. No dual booting. Only Trisquel GNU/Linux 10.0.1 is installed on this x220 (with BIOS).

> What did you do before the error started?

I was trying to format a USB stick to FAT from ext4 from the command line. I would not be able to recall which commands I run.

From https://www.diskpart.com/articles/grub-rescue-unknown-file-system-0825.html: I tried "Method 2", unfortunately, I cannot locate the partition using ls in grub. That is why I was thinking I should try to fix my issue from a live boot, maybe with the suggestion mentioned in https://askubuntu.com/questions/142300/how-to-fix-error-unknown-filesystem-grub-rescue for example:

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

> One case is for attempting a dual boot with Windows and the other is attempting to dual boot with OS X. But what's your case?

The laptop only has Trisquel installed (no Windows, no OS X).

Please let me know what I could try to troubleshoot, or if you need further information from my end.

Staircase
Desconectado
Joined: 02/24/2022

I picked a new drive and restored from backup for now as I have not been able to figure why "grub rescue> ls" does not locate any partition.

Any tip on how to troubleshoot would be welcomed.

prospero
Desconectado
Joined: 05/20/2022

> I picked a new drive and restored from backup

That's the best tip I could think about.

Assuming you now have a running system on your new drive, with all your personal files on it, I believe you could format your old drive and keep it as a spare.