grub-pc versus grub-efi-amd64

[Volker Wysk]

Am Dienstag, den 01.09.2020, 23:54 +0200 schrieb Tom H:
> On Tue, Sep 1, 2020 at 2:19 PM Volker Wysk <post at volker-wysk.de>
> wrote:
> > Am Montag, den 31.08.2020, 20:57 +0200 schrieb Tom H:
> > > On Mon, Aug 31, 2020 at 7:02 PM Volker Wysk <post at volker-wysk.de>
> > > wrote:
> > > > Am Montag, den 31.08.2020, 14:27 +0200 schrieb Tom H:
> > > > > On Sat, Aug 29, 2020 at 5:31 PM Volker Wysk <
> > > > > post at volker-wysk.de>
> > > > > wrote:
> > > > > I installed 20.10 right after 20.04 was released on an EFI
> > > > > system, and I also have "grub-pc" rather than "grub-efi-
> > > > > amd64"
> > > > > installed.
> > > > 
> > > > And this isn't a packaging bug...
> > > 
> > > I don't think so. I _feel_ that it's more likely to be an apt
> > > bug.
> > 
> > So you *do* think that it's a bug - that grub-efi-amd64 should be
> > installed rather than grub-pc.
> 
> It looks like an esoteric apt resolver bug, but not a packaging bug.
> 
> 
> > And installing grub-efi-amd64, to replace grub-pc, really really
> > won't break the system..? I'm hesitant...  :)
> > 
> > There is quite something happening when doing it:
> > 
> > -----snip-----
> > desktop ~ % apt --simulate install grub-efi-amd64
> > (...)
> > Inst grub2-common [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> > Ubuntu:20.04/focal-updates [amd64]) [grub-pc:amd64 ]
> > Remv grub-pc [2.04-1ubuntu26.2] [grub-gfxpayload-lists:amd64 grub-
> > efi-
> > amd64-signed:amd64 ]
> > Inst grub-efi-amd64 (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> > [amd64]) [grub-gfxpayload-lists:amd64 ]
> > Remv grub-gfxpayload-lists [0.7] []
> > Inst grub-pc-bin [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> > Ubuntu:20.04/focal-updates [amd64]) []
> > Inst grub-efi-amd64-signed [1.142.4+2.04-1ubuntu26.2]
> > (1.142.5+2.04-
> > 1ubuntu26.3 Ubuntu:20.04/focal-updates [amd64]) []
> > Inst grub-efi-amd64-bin [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> > Ubuntu:20.04/focal-updates [amd64]) []
> > Inst grub-common [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> > Ubuntu:20.04/focal-updates [amd64])
> > Conf grub2-common (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> > [amd64])
> > Conf grub-efi-amd64 (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> > [amd64])
> > Conf grub-pc-bin (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> > [amd64])
> > Conf grub-efi-amd64-signed (1.142.5+2.04-1ubuntu26.3
> > Ubuntu:20.04/focal-updates [amd64])
> > Conf grub-efi-amd64-bin (2.04-1ubuntu26.3 Ubuntu:20.04/focal-
> > updates
> > [amd64])
> > Conf grub-common (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> > [amd64])
> > -----snip-----
> 
> You have a very different installation from mine.
> 
> How can you not have "grub2-common" already installed? 

It *is* installed, but upgradable:

-----snip-----
desktop ~ $ LANG=C apt list grub2-common -a
Listing... Done
grub2-common/focal-updates 2.04-1ubuntu26.3 amd64 [upgradable from:
2.04-1ubuntu26.2]
grub2-common/focal-security,now 2.04-1ubuntu26.2 amd64
[installed,upgradable to: 2.04-1ubuntu26.3]
grub2-common/focal 2.04-1ubuntu26 amd64
-----snip-----



> What's the
> output of "which grub-install"?

desktop ~ $ which grub-install
/usr/sbin/grub-install

desktop ~ $ apt-file search /usr/sbin/grub-install
grub2-common: /usr/sbin/grub-install      
lupin-support: /usr/sbin/grub-install


> I don't understand why "grub-pc-bin" is installed alongside
> "grub-efi-amd64" and when "grub-pc" is being removed, but it's too
> late to go through the dependencies and figure it out...

I understand even less...


> > > > What disturbs me, is that the "update-grub" script is in the
> > > > "grub-pc" package, but not in "grub-efi-amd64". Isn't this
> > > > script
> > > > needed, for instance, when a new kernel is to be installed?
> > > 
> > > "update-grub" in "grub-pc" is the legacy "update-grub" script,
> > > which
> > > means that it is "update-grub" of grub1. Running grub1's "update-
> > > grub"
> > > would update "/boot/grub/menu.lst" in between "BEGIN AUTOMAGIC
> > > KERNELS
> > > LIST" and "END DEBIAN AUTOMAGIC KERNELS LIST" lines.
> > 
> > Does that mean that "update-grub" is obsolete? I recall vaguely
> > that
> > it used to be executed whenever a new kernel gets installed. Is
> > this
> > no longer the case with Grub2?
> 
> grub2's update-grub is "/usr/sbin/update-grub".

Yes, it's in grub2-common as well as in grub-pc. So it will still be
there, when grub-pc gets replaced. It isn't obsolete.


I've come to the conclusion not to touch the packages, unless I really
need to. I'll file a bug report next.

Thanks for your help!

Volker
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