Reinstall Boot Only

I upgraded the hardware on my server.
Replaced everything except Power Supply and Harddrives.

It will not boot into Linux, only into the BIOS.
In BIOS it does detects all the harddrives, but my Linux OS SSD is not detected as a bootable drive, so no drives appears in the boot priority list.

I guess it might have something to do with my boot partition is old, and not EFI.

I do not want to loose my server software to do a fresh reinstall.
Although perhaps I could take backup and restore after a fresh reinstall.

Is it possible to repair, reinstall boot partition only, without having to reinstall the whole shabang?

What options do I have?
Can the Live USB perform a repair, or reinstall with only formatting the boot partition, and leave the / partition as it is?

Have you set the BIOS/UEFI to boot in legacy mode (MBR)

I could not find an option for Legacy boot when I was going through my BIOS yesterday.
But I will try to look again.
How to Change the Boot Mode (UEFI/Legacy) on Intel® Server Boards

Boot the live USB.

Mount your root file system at “/mnt”.

And then (as root):

mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
chroot /mnt

That should put you in a chroot command line environment for your mounted system.


mount -a

That should mount all needed file systems.

While still in that chroot environment


That should give you an ncurses version of yast. It’s a little harder to use than the normal GUI version, but it should work.

Use “System” → “boot loader”

Try changing something. The easiest is to just change the timeout by 1 second. When you accept those changes, yast should reinstall the bootloader for you.

Assuming it was EFI in the past. But it is rather unclear from description so far. One should really start with obligatory fdisk -l, blkid and cat /etc/fstab output.

I do not have EFI on the existing boot partition.

Still cannot find any configuration in BIOS for Legacy Boot Mode.

My motherboard is Asrock Z590 Pro4.

Secure Boot is disabled in BIOS.

I was able to boot into the OS through using a Leap 15.4 USB stick.

I was thinking of trying to run the Upgrade option through the USB stick.
Would this allow me to fix/reformat the boot partition only, while simultaneous upgrade to 15.4?

You probably have to look for “Compatibility Support Module (CSM)” to find the legacy boot options.

I could not enable CSM.
It said I needed a graphic card to enable it.

If you don’t have room to simply add another small partition to an existing disk for EFI booting, you could install a low cost stick, around $20US or less for 120G, in one of your M.2 slots to put one on, then convert to EFI booting of your existing installation. Probably you could clone your system partition from an old SSD or HDD to an NVME stick and upgrade that to 15.4, preserving everything as-is on the old. I have a really old RAID1 with TW and 15.4 on a newer motherboard and boot the old TW on RAID from the NVME’s ESP. Booting the installed OS from installation media should enable you to use YaST Bootloader to setup ESP booting once you have an ESP location. The OS doesn’t really care how the kernel and initrd get loaded. Or you could just install fresh 15.4 on an NVME, and multiboot from ESP until you can migrate the older software onto the newer installation.

Some partitioners can convert MBR tables into GPT tables to facilitate a migration to a motherboard lacking CSM bootability.

IOW, making the existing installation bootable from an ESP is doable, one way or another. Once we know your existing partitioning, recommendation(s) can be made.