How to restore the MBR after do-release-upgrade?

[Tom H]

On Sat, Jul 9, 2016 at 12:38 PM, Ralf Mardorf <silver.bullet at zoho.com> wrote:
> On Sat, 9 Jul 2016 12:04:51 -0400, Tom H wrote:
>>
>> It's the kernel that depends on grub. It makes sense for Ubuntu to do
>> so because, if a user's not installing in a container (and therefore
>> not in need of a kernel), he doesn't need a bootloader.
>
> I need a kernel, because I only run it in a container to maintain it,
> but to use it, I need to "really" boot it. Anyway, I wasn't aware that
> it is possible to remove all kernels. If I would run it in a
> container, remove all kernels before a release upgrade, then the
> release upgrade doesn't install a kernel? This would be the best
> workaround, since after the release upgrade I could install a kernel
> without recommended packages or simply install a grub-pc dummy
> package, before installing it.

Rather than re-installing a kernel, you could uninstall the kernel and
grub and, if you really need a kernel inside the container, copy the
host's "/boot/vmlinuz-$KERN", "/boot/initramfs-$KERN", and
"/lib/modules/$KERN/" to its container - and update grub.cfg.