GRUB starts in command line after reboot

Question

I installed Linux Mint on my laptop along with a pre-installed Windows 10. When I turn on the computer, the normal GRUB menu appears most of the time:

But after booting either Linux or Windows then rebooting, I GRUB starts in command line mode, as seen in the following screenshot:

There is probably a command that I can type to boot from that prompt, but I don't know it. What works is to reboot using Ctrl+Alt+Del, then pressing F12 repeatedly until the normal GRUB menu appears. Using this technique, it always loads the menu. Rebooting without pressing F12 always reboots in command line mode.

I think that the BIOS has EFI enabled, and I installed the GRUB bootloader in /dev/sda.

Why is this happening and how can I ensure that GRUB always loads the menu?

Edit

As suggested in the comments, I tried purging the grub-efi package and reinstalling it. This did not fix the problem, but now when it starts in command prompt mode, GRUB shows the following message:

error: no such device: 6fxxxxx-xxxx-xxxx-xxxx-xxxxxee.
Entering rescue mode...
grub rescue>

I checked with the blkid command and that is the identifier of my linux partition. Maybe this additional bit of information can help figure out what is going on?

Answer 1

The boot process can't find the root partition (the part of the disk, that contains the information for starting up the system), so you have to specify its location yourself.

I think you have to look at something like this article: how-rescue-non-booting-grub-2-linux

short summary:

in the grub rescue> command line type

ls

... to list all available devices.
Then you have to go through each, type something like (depends what is shown by the ls command):

ls (hd0,1)/
ls (hd0,2)/ 

... and so on, until you find:

(hd0,1)/boot/grub   OR (hd0,1)/grub

... or, in case of "UEFI", it look something like:

(hd0,1)/efi/boot/grub OR (hd0,1)/efi/grub

Now you have to set the boot parameters accordingly - just type the following (with the correct numbers for your case) and after each line press return:

set prefix=(hd0,1)/grub

... or (if grub is in a sub-directory):

set prefix=(hd0,1)/boot/grub

Then continue with

set root=(hd0,1)
insmod linux
insmod normal
normal

Now it should boot:

boot

Go to the commandline (e.g. start a "terminal") now, and execute:

sudo update-grub

... this should correct the missing information and it should boot next time.

If NOT - you have to go through the steps again an might have to repair or install grub again:
Please look at the "Boot-Repair"-tool from this article: https://help.ubuntu.com/community/Boot-Repair (I had positive experiences with it, when previous steps wouldn't survive the reboot)

Answer 2

This is some funny thing happening to many PC dual booting with Windows 10. Happened to me and friends recently. Please note that I don't know why, I can only speculate this depends on some Windows 10 updates. As someone said, indeed this is due to the boot process not finding the root partition for some reason, so GRUB asks you to tell him where it is via CLI.

Anyway thanks for asking this question, I found it trying to fix my problem and I created this account just to answer this. The fix is super easy :

• go to BIOS/UEFI
• check the boot partitions: are there ok or too many? do you recognize all of them? Remove the ones that are not needed.
• reset the boot order to default
• restart, you should see the usual GRUB menu

Answer 3

You can boot your linux system through Super Grub2 disk, Download the iso from here and create a bootable USB

After successfully booting kali linux , reinstall grub-efi as follows :

grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=debian --recheck --debug /dev/sda
update-grub

Answer 4

I suddenly found that after some updates Windows has set the Fast boot option to enabled. And that caused my ubuntu boot problem)) Fast boot option can be found somewhere in your BIOS/boot settings

Answer 5

I ran into the same issue. And I found that sometimes when booting in windows 10 the boot order is changed. I have two SSDs in my laptop. One has ubuntu and grub and the other has windows installed. The boot order is sometimes changed when windows 10 updates and puts the windows SSD first, causing the system to always boot into windows. Recently it randomly changed it and I started seeing the system boot into the grub prompt. Once I changed the boot order in BIOS, the grub menu loaded normally.

Answer 6

If entering 'exit' on the GRUB command prompt brings you to the GRUB menu, it could be an issue with the boot priority sequence in your BIOS utility.

For me the fix was to reorder the boot sequence - I entered my BIOS utility on startup and reordered the 'UEFI Hard Disk Drive Priorities' so that the Ubuntu partition was first in line.

My understanding is that entering 'exit' on the GRUB menu will quit GRUB and cause the BIOS to try and start the next available bootloader.

Answer 7

Your Windows may be installed in UEFI boot mode and Mint in BIOS boot mode. The two modes are not compatible and you can only dual boot from UEFI/BIOS menu and may have to turn on or off UEFI or BIOS boot settings. Grub can only dual boot other installs in same boot mode as you booted grub. You can use Boot-Repair to convert a BIOS.

Answer 8

If you happen to boot into GRUB menu:

1. Start your system

1.1 Figure out which partition is the system one via mounting available partitions and looking for executable kernel file:

grub> ls # shows list of disks and partitions available
(hd0,gpt1), (hd0,gpt2) # you might have other things listed here
grub> set root=(hd0,gpt1)
ls /boot # if theres a file called vmlinuz<version> or initrd<version>, bingo!

If there's no vmlinuz file, call unset root and try with another one set root=(hd0,gpt2)

1.2 Load a linux kernel:

grub> linux /boot/vmlinuz-<version> # use TAB to autocomplete version. if theres multiple versions, use whatever

1.3 Load a linux initrd file:

grub> initrd /boot/initrd.img-<version> # same deal, use TAB to autocomplete version

1.4 Boot up your system:

grub> boot

2. Reinstall grub

2.1 Make sure `grub-install` is there:

sudo apt-get install grub-install

2.2 Reinstall grub for the mounted disk:

sudo grub-install /dev/sdX

sdX means a device mounted in step 1. If not sure, issue lsblk and look for the device which has / mountpoint:

$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 223.6G  0 disk              <-- in my case, sdX = sda
├─sda1   8:1    0   100M  0 part /boot/efi
├─sda2   8:2    0 130.9G  0 part /mnt/windows
├─sda3   8:3    0    28G  0 part /            <-- because this is under sda
├─sda4   8:4    0   7.9G  0 part [SWAP]
├─sda5   8:5    0   128M  0 part
└─sda6   8:6    0  56.6G  0 part /home

2.3 Reboot

systemctl reboot

At this point, GRUB bootloader should work as you intend so.

References/similar issues:

• https://www.gnu.org/software/grub/manual/grub/html_node/Command_002dline-and-menu-entry-commands.html

• https://www.unixmen.com/fixing-a-few-common-grub-errors-broken-bootloader-and-error-1715/

Answer 9

Try these commands

Repeat this for all listed partitions until you find a result that includes something like initrd.img-... vmlinuz-... or even /grub.

Once you find a partition that contains your Linux Mint boot image you will run the following steps:

You should initialize kernel

grub> set root=(hd0,1)
grub> linux /vmlinuz-4.4.0-38-generic 
grub> initrd /initrd.img-4.4.0-38-generic
grub> boot

grub> set root=(hd0,[partition number you found])/boot
grub> insmod linux
grub> linux (hd0,[partition number you found])/boot/vmlinuz-[image name]
grub> initrd ((hd0,[partition number you found])/boot/initrd.img-[image name]
grub> boot

Once booted into your Linux Mint install and not a rescue disk or anything if you see that you are missing Windows from GRUB you will need to follow these steps:

sudo os-prober \\ If you see your Windows Partition then you can run the next step
sudo grub2-mkconfig
sudo update-grub

Answer 10

After spending a while on this page, here is what worked for me:

Check each of the partitions until you find one with vmlinuz and initrd on. This could be in the same partition as root or (not in my case).

There will be one partition (root) you find with bin/ and boot/ etc in. If you "ls" in the boot folder and it's empty, you will have to look for vmlinuz somewhere on another partition.

(hd0,msdos1) corrisponds to /dev/sda1.
(hd1,msdos4) corrisponds to /dev/sdb4

set root = (hd0,msdos6)
linux (hd0,msdos1)/vmlinuz root=(hd0,msdos6)
initrd (hd0,msdos1)/initrd 

Note:

• After typing vmlinuz you can press tab for autocomplete.
• Replace (hd0,msdos1) with where vmlinuz and initrd are
• Replate (hd0,msdos6) with the typical root parition, you should find bin/ boot/ home/ etc/ in here.

Pressing enter should lead you back into Ubuntu. If it does not, you got your partitions wrong.

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

Note: - The lack of numbers after /dev/sda

TL;DR - Read this: How to Rescue a Non-booting GRUB 2 on Linux

Answer 11

The same issue occurred on my dell laptop with windows 10 and Linux mint 19. So what happened was I was working windows and suddenly the hdd was missing from the disk list. Window was working fine since it was on ssd drive. After being confused for a while I wanted to make sure if the hdd was functioning so I run a diagnostic from the bios after it was done I restarted the machine and got my grub listing back.

Answer 12

After installing Linux Mint 19.1 the system would only boot to the grub rescue> prompt and displayed an error just above it indicating it could not find hd0. Thanks to this thread I accessed the BIOS and under "Storage/Storage Options" I changed the SATA emulation from AHCI RAID to Native Mode IDE and now the system boots up to the proper menu which allows me to choose my Linux Distribution and continue booting successfully.

Answer 13

Reinstall Linux on same partition, take care of foll. things this time:

1. Start Live and then install
2. Once installation is over, DO NOT Reboot
3. Close the dialog box, and open Terminal Ctrl + Alt + T
4. Type following command- sudo update-grub

5. Reboot if successfully done

Answer 14

I had this problem with Ubuntu. I went into BIOS and disabled Intel Encryption, Secure Boot, and anything else that looked vaguely like a security feature. Then installed Ubuntu again and it installed fine.

Answer 15

I copied my kubuntu 19.10 partition from hd to SSD to make the system work faster and didn't want to reinstall everything over again. I want to keep the original partition as a backup since I want to experiment with davinci resolve. So I changed UUID using Gparted. Then I got the Grub 2.02 "Mininal BASH-like line editing..." error. All I did was to booted into setup and changed the boot order to get it fixed. Now I see Kubuntu 19.10 on sda11, windows on sda1 and kubuntu 19.10 on sdb2. I hope it'll help someone.