Le 21/05/2021 à 10:24, Chris Green a écrit :
How should I do the changes to /boot/grub/grub.cfg? Do I edit
/etc/default/grub and then run grub-mkconfig? However I don't really
see how this would work, I can set the output file for grub-mkconfig
but how do I tell it to use the /etc/default/grub in /dev/sdc1?
You can either run grub-mkconfig or edit /boot/grub/grub.cfg manually.
If you choose to use grub-mkconfig, you must run in while /dev/sdc1 is
the root, either by booting it or by chrooting into it from the original
system.
At what stage does the copy in /dev/sdc1 get added to my boot menu?
After you run update-grub or grub-mkconfig in the original OS.
I would also install GRUB on /dev/sdc from the copy to be able to boot if
the original installation is so broken that even GRUB does not work any
more.
Definitely, is that just a matter of booting the copy OS and running
grub-install?
You don't even need to boot (or chroot) into the copy OS. You can run
# grub-install --boot-directory=/mnt /dev/sdc
in the original OS.
