Re: status: how to install grub to non-bootable RAID-formatted drive?

["Alexander V. Makartsev" <avbetev@gmail.com>]

On 1/29/26 02:03, D. R. Evans wrote:

> Alexander
>       V. Makartsev wrote on 1/28/26 10:55 AM:
>       
> > That is strange, how old is your hardware?
> >         When you mentioned 2013 I was
> >         
> >         thinking 4th gen Intel CPU and Haswell-era hardware, which
> >         should
> >         
> >         support USB-boot.
> >         
> >       
>       
>       OK... on the basis of the fact that you expected USB boot to work,
>       I just went and spent some time messing with the boot options, and
>       found a way to make it work. What I had not realised was that it
>       was not enough to select "USB-HDD" from the BIOS list, but I also
>       had to then go and look at the hard drive boot order, where a new
>       entry had appeared (at a low priority). Once I saw that and
>       changed its priority so that it was the preferred boot device, the
>       machine booted fine from the USB drive.
>       
>       
>       All this, I'm sure, is very elementary stuff... but if one has
>       never encountered it before, as I have not, none of it was
>       obvious.
>       
>       
>       So the next bit of your e-mail (about the motherboard and booting)
>       no longer applies. 
    I think it does. 
    Because with the last bits of information I can tell there is
    nothing wrong with grub config file and OS config files (you did
    "update-initramfs" and "dpkg-reconfigure" from previous email
    right?).
    All partition\array UUIDs are detected by grub, they all match and
    at their places across many config files and during boot time.
    Your MD RAID1 setup is extremely ordinary, it should work without
    any hickups, but it doesn't.
    Except maybe weirdly configured and inactive array /dev/md127 on
    /dev/sda1 which meant to be used as swap.
    So, I'd continue by fixing it.
    I still want to know the details about your motherboard. Maybe there
    is a BIOS update, or this is known issue with larger AF disks and
    MBR style partition table, you never know.
    Everything I've suggested so far is something I would try myself, if
    I had the same problem and conditions as you have.
    
> ...
>       I'll pause there, so you have a chance to look at that, and I have
>       a chance to look at the grub rescue stuff ... and also try put out
>       another (unrelated) urgent fire. 
>     
    I imagine you could type at grub rescue prompt something like this:
    grub> set pager=1
      grub> insmod normal
      grub> insmod part_msdos
      grub> insmod diskfilter
      grub> insmod mdraid1x
      grub> insmod ext2
      grub> ls
      (proc) (hd0) (hd0,msdos1) (hd0,msdos2) (md/0)
      grub> set prefix=(md/0)/boot/grub
      grub> set root=(md/0)
      grub> linux ($root)/boot/vmlinuz-6.12.63+deb13-amd64
      root=/dev/md126
      grub> initrd ($root)/boot/initrd.img-6.12.63+deb13-amd64
      grub> boot
      
    Note: your md devices could be named differently there, maybe
    not "(md/0)" and "root=/dev/md126", because one of your raid1 arrays
    is not functioning.
    And you don't need to type "grub>", obviously..

--

 With kindest regards, Alexander.

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