Re: Advise on how to debug screen with only GRUB and blinking cursor and possibly save my dualboot installation

[Pascal Hambourg]

On 19/12/2022 at 21:10, Sophoklis Goumas wrote:
>   => Grub2 (v1.99-2.00) is installed in the MBR of /dev/sda and looks at sector
>      2048 of the same hard drive for core.img, but core.img can not be found at
>      this location.
>
> sda1: __________________________________________________________________________
>
>      File system:       BIOS Boot partition
>      Boot sector type:  -
>      Boot sector info:

> sda:1000GB:scsi:512:4096:gpt:ATA WDC WD1003FZEX-0:;
> 1:1049kB:2149MB:2147MB:ext4::bios_grub, legacy_boot;

> NAME   FSTYPE               UUID                                 PARTUUID
> sda
> ├─sda1  ext4  52a151cd-0ad7-4455-b445-cfe72d775605  
> 05f43beb-995b-4403-afcd-196ac65dd92f

> Mount points (filtered): _______________________________________________________
>                                              Avail Use% Mounted on
> /dev/mapper/sojourn-home                     4.4G  94% 
> /mnt/boot-sav/mapper/sojourn-home
> /dev/mapper/sojourn-opt                     10.1G  25% 
> /mnt/boot-sav/mapper/sojourn-opt
> /dev/mapper/sojourn-root                    54.7G   1% 
> /mnt/boot-sav/mapper/sojourn-root
> /dev/mapper/sojourn-tmp                      6.8G   0% 
> /mnt/boot-sav/mapper/sojourn-tmp
> /dev/mapper/sojourn-usr                      5.1G  89% 
> /mnt/boot-sav/mapper/sojourn-usr
> /dev/mapper/sojourn-var                    460.6M  93% 
> /mnt/boot-sav/mapper/sojourn-var
> /dev/sdb1                                    1.5G  99% /mnt/boot-sav/sdb1
> /dev/sdb2                                   86.5M  83% /mnt/boot-sav/sdb2
> /dev/sdb3                                     12G  97% /mnt/boot-sav/sdb3
> /dev/sdb4                                    1.8G  99% /mnt/boot-sav/sdb4

It looks like we have conflicting information here.
- GRUB core image is not found at sector 2048 (sda1).
- but sda1 file system is identified as "BIOS Boot partition".
- parted and blkid find a ext4 filesystem in sda1.
- but sda1 is not mounted

Maybe the ext4 filesystem which was mounted on /boot and the GRUB core 
image corrupted each other.

Can you mount /dev/sda1 ?
Can you show the contents of /boot and /etc/fstab in mounted 
/dev/mapper/sojourn-root ? Unfortunately boot-repair did not.