Re: Broken UEFI Dual boot : Debian 12 + encrypted Debian 11
On Tue 23 Nov 2021 at 16:50:30 (+0100), Yvan Masson wrote:
> Le 23/11/2021 à 13:57, Yvan Masson a écrit :
> > I have a laptop with two drive, historically installed with an
> > encrypted Debian 11 booting in UEFI mode (done with Debian
> > Installer).
> >
> > I just installed Debian 12 without encryption in a small
> > partition. Unfortunately, I can not boot Debian 11 anymore,
> > grub-efi only shows the Debian 12 install.
> >
> > Any help to make both install boot would greatly appreciated.
> > Being able to boot Debian 11 only would also be great if the dual
> > boot is not possible.
It sounds like when you installed 12, your encrypted partition for 11
was still locked, and so the os-prober couldn't find it. When in 12,
you need to unlock 11 and then update grub so it can include 11 in its menu.
> I found first an answer for the second question : the wiki
> (https://wiki.debian.org/GrubEFIReinstall) explains exactly how to
> recover from such issue. This is what I did and I can now only boot on
> my encrypted Debian 11.
>
> For the first question, I found different solutions on AskUbuntu (https://askubuntu.com/questions/617045/how-do-i-install-two-independent-ubuntu-installations-on-a-single-hard-drive-wit)
> : I chose the method with two EFI partitions, because it seems easier
> to me (but this might no be true). If you do this, do not forget to
> modify /etc/fstab so that each install uses the proper EFI partition.
I've no experience with doing that. I've always set up grub-install
to point to the device that contains /boot belonging to the system
I want to boot up by default, and then used update-grub to make that
/boot/grub/grub.cfg aware of all the systems on the machine (but
they all need to be visible so that they get entries added). This
latter grub.cfg will boot this same system by default.
Cheers,
David.
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