Can't load ubuntu, boot failure

Support & Help Requests
1

Hi mate-friends,
I think I made mistakes during installion of 20.04 because after running a month I shut down and now I can't load ubuntu, I come to GRUB and get

         > GNU GRUB version 2.04

Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions.

grub> _

Grub doesn't respond to "boot", it only gives me:
you have to load the kernel first

I have 2 drives in my computer, 1 HDD 4TB (with all my files) and then 1 SSD whick is entierly dedicated to the system. In the bootmeny the SSD is first on the list so that seem correct but it sill not boot from there.
With help of my memory stick with ubuntu I got in to fiddel around and in the terminal I wrote and got:

ubuntu-mate@ubuntu-mate:~$ lsblk -o NAME,LABEL,FSTYPE,SIZE,TYPE,MOUNTPOINT
/dev/loop0 /dev/loop3 /dev/sdb /dev/sdb5 /dev/sdc2
/dev/loop1 /dev/loop4 /dev/sdb1 /dev/sdc /dev/sdc3
ubuntu-mate@ubuntu-mate:~$ lsblk -o NAME,LABEL,FSTYPE,SIZE,TYPE,MOUNTPOINT | grep ext[0-9]
sda Busk ext4 3.7T disk
└─sdb5 ext4 111.3G part
└─sdc3 writable ext4 4.5G part /var/crash

It didnät spot my SSD so I used GParted and found it:

Partition filesystem size used flags

/dev/sdb1 fat32 512MB 5.48MB boot
/dev/sdb2 extended 111.29GB ----
/dev/sdb5 ext4 111.29GB 16.18GB

It doesn't say that anything is wrong, right?

I've been using ubuntu since 2009 so I ought to be savvy but since my eye-sight was damaged I just do what I can and get by, it's dificult to search the web for answers now.

If anyone thick it's poossible to salvage this, and that I can manage it, please guide me through it!
Otherwise I will need help with re-installing.

Thanks for reading to the end! :crazy_face:

2

Ubuntu is on /dev/sdb, sdb1 is the /boot/efi and sd5 is your / partition.

sudo mount /dev/sdb5 /mnt   
for i in /dev /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt
mount /boot/efi
grub-install /dev/sdb 
update-grub

if successful, reboot and hopefully your system will come up.

1 Like
3

Hi and thanks for your answer! This is what I got

root@ubuntu-mate:/# sudo mount /dev/sdb5 /mnt
root@ubuntu-mate:/# for i in /dev /proc /sys /run; do sudo mount -B $i /mnt$i; done
root@ubuntu-mate:/# sudo chroot /mnt
root@ubuntu-mate:/# mount /boot/efi
root@ubuntu-mate:/# grub-install /dev/sdb
Installing for i386-pc platform.
Installation finished. No error reported.
root@ubuntu-mate:/# update-grub
Sourcing file /etc/default/grub' Sourcing file /etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.13.0-30-generic
Found initrd image: /boot/initrd.img-5.13.0-30-generic
Found linux image: /boot/vmlinuz-5.13.0-28-generic
Found initrd image: /boot/initrd.img-5.13.0-28-generic
Found linux image: /boot/vmlinuz-5.13.0-27-generic
Found initrd image: /boot/initrd.img-5.13.0-27-generic
Found memtest86+ image: /boot/memtest86+.elf
Found memtest86+ image: /boot/memtest86+.bin
grub-probe: error: cannot find a GRUB drive for /dev/sdc1. Check your device.map.
done
root@ubuntu-mate:/#

Could the error have to do with the Live Ubuntu I'm using?

4

You need to boot off a live usb, your prompt shows that you did not. I would suggest to unplug the sdc drive so the system should have just one drive. It is possible that if one drive is detected, it will become sda so adjust my commands to sda. lsblk -f should show drive. Please post this info.

After your system is fixed and boots properly, you can plug sdc back in and possible fix /etc/fstab so that it is mounted upon boot.

example of lsblk -f (drive mounts sda2 to / , sda1 to /boot/efi , sdb is mounted as /data)

NAME   FSTYPE LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINT
sda                                                                     
├─sda1 vfat         D035-2697                             505.8M     1% /boot/efi
└─sda2 ext4         92ab6051-649a-4d52-b775-6364e7e5ddd1   81.8G    20% /
sdb                                                                     
└─sdb1 ntfs   data  6F4B577810F8E7C7                       86.4G    63% /data
5

Now I'm lost; should I unmount sdc - which is the USB-drive - I can't access the terminal to write the commands.?
Also, why change the command to "sda" that is the HDD-drive with my files and can't contaion any of the system-files.
So confusing....

6

You have a desktop with an ssd, UM20.04

Upon boot it gives you the grub> prompt so you need to fix it. Am I correct?

I suggested, temporarily disconnect the 4T drive so the pc has just the ssd.

Plug in a live USB and boot from that (Try ubuntu).

If you type lsblk -f it shows the ssd drive. Correct? make note which partition has mountpoint / Then, apply the commands I suggested. If all goes well, reboot, your system should come up.

Shutdown, reconnect the 4T where your files are, and reboot. You should have a working system and you can mount the 4T drive.

7

I see, that makes sense. Only I'm visually impaired so I shouldn't play around inside! Those times are gone sadly.
It was a great idea though.