(SOLVED) Re: GRUB trouble, Help needed

[Volker Wysk]

Am Samstag, den 05.10.2019, 18:44 +0200 schrieb Volker Wysk:
> Hi.
> 
> I have been building a maintenance system on an USB stick, and
> botched
> it. I've used the Ubuntu installer and the MBR got written to the
> wrong
> disk, namely the first hard disk (an SSD in my case) instead of the
> USB
> stick.
> 
> I've done it again, doing it right, and can now boot from the new USB
> stick. But I can't boot my main system any longer, which had been
> started from /dev/sda. 
> 
> I can access my encrypted root partition from the maintenance USB
> stick, and mounted it to /mnt/root. Then I've tried this: 
> 
> mount --rbind /dev /mnt/root/dev
> mount --rbind /proc /mnt/root/proc
> mount --rbind /sys /mnt/root/sys
> chroot /mnt/root
> update-initramfs -u
> grub-install /dev/sda
> update-grub
> 
> This is by Colin Watson in ubuntu-users at Mon, 3 Sep 2018. He said
> it
> goes "roughly" like this.

I've found out what went wrong. I forgot to mount the /boot partition
on the main system, before doing the procedure above. It should go:

mount --rbind /dev /mnt/root/dev
mount --rbind /proc /mnt/root/proc
mount --rbind /sys /mnt/root/sys
mount /dev/sda1 /mnt/root/boot
chroot /mnt/root
update-initramfs -u
grub-install /dev/sda
update-grub
 

Cheers,
Volker