How to get back Windows on the grub menu?

[Bo Berglund]

On Wed, 27 Oct 2021 16:07:27 +0100, Liam Proven <lproven at gmail.com> wrote:

>On Wed, 27 Oct 2021 at 15:50, Bo Berglund <bo.berglund at gmail.com> wrote:
>Looks like just 1 ESP. Good!
>
>> >It is mounted under `/boot/efi`?
>>
>> Not mounted as far as I can see:
>> # mount | grep "/boot"
>> returns nothing.
>
>That is bad.
>
>The ESP needs to be mounted onto the existing, hopefully empty, folder
>
>/boot/efi

I mounted it to /mnt/efi so as not to mess with /boot
The mount contains this amount of data:
$ sudo du -sh /mnt/efi
34M     /mnt/efi

>
>See here:
>https://superuser.com/questions/1430485/ubuntu-18-04-cannot-mount-boot-efi
>
>> So should I just mount them like this temporarily:
>> /mnt/win (nvme0n1p3)
>> /mnt/desk (nvme0n1p5)
>
>Anywhere you like, really, so long as the `os-prober` tool can see them.
>

Does os-prober (called from update-grub) search the system it runs on for
mounted partitions anywhere or maybe using the mount command to list them?
Or do I have to supply the locations somehow?

I can esily do these mounts juist for the grub update:
/mnt/efi
/mnt/server20
/mnt/desktop20
/mnt/windows

>> Is the idea to then issue:
>> # update-grub
>
>Yes, that's correct.

>From the Ubuntu desktop version then?

>> I have searched a lot to get to the state I posted earlier where I now have a
>> really awkward method to switch between two different grub boot menus.
>
>You have 2 different GRUB menus on the hard disk? (Not counting
>bootable USBs etc.)

If I just reboot from any of the 2 Ubuntus I get to a boot menu which lists only
these two operating systems (and advaced options for each).

But if I go through the hoops I described earlier when I need to run Windows to
finally reach the USB Live device, then as part of the reboot another boot menu
looking in principle as the first one appears.

But it does *not* contain the server 20.04 instead it contains Ubuntu server
18.04 (so before it was release-upgraded) AND Windows.
So there are two different looks of the boot menu and that is my main issue
here.

I would like to have only one boot menu, but it should contain also Windows and
the Ubuntu entries should state if they are desktop or server so it is possible
to choose the right one to load.
Is it possible to edit the boot menu text display somehow?


I think the menu containing Windows was created when I installed Ubuntu desktop
20.04 from USB live media at the beginning of this endeavour.
Then when I booted to Ubuntu 18.04 server and ran the release-upgrade in the
process it might have changed the boot menu to what I have now with two
different versions.
Or it might have been when I ran the update-grub after removing the backup drive
containing the partitions I had moved over to the main disk of the new PC.
I did that because the boot menu then had too many entries including references
to the USB connected backup drive operating system partitions...

>
>> The desktop was installed here from live media when I was able to do this
>> easily. So its installer should have seen the EFI/UEFI stuff.
>
>Ideally use this version to manage GRUB.

That would mean booting up the Ubuntu 20.04 *desktop* and then mounting the EFI
partition plus the ubuntu server and Windows partitions before running
update-grub?

>> My fear now is that by doing anything to GRUB I might destroy the possibility to
>> actually do the workaround and am stuck with a system that cannot be backed up
>> fully...
>
>Well, you can back up the EFI like any other partition...

It is already on the backup disk; a couple of days ago I used GParted Live to
back up all of the partitions to the 1TB backup drive.
Took a long time probably because that drive is a USB2...

I should get myself a USB3 case to put the drive into...


-- 
Bo Berglund
Developer in Sweden