GRUB BIOS boot packages

[keeka]

Since I am booting via EFI, do I still need to retain grub-pc-bin package?

# dpkg --list | grep grub
ii  grub-common                          2.06-13+pmx2                        amd64        GRand Unified Bootloader (common files)
ii  grub-efi-amd64                       2.06-13+pmx2                        amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 version)
ii  grub-efi-amd64-bin                   2.06-13+pmx2                        amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 modules)
rc  grub-pc                              2.06-13+pmx1                        amd64        GRand Unified Bootloader, version 2 (PC/BIOS version)
ii  grub-pc-bin                          2.06-13+pmx2                        amd64        GRand Unified Bootloader, version 2 (PC/BIOS modules)
ii  grub2-common                         2.06-13+pmx2                        amd64        GRand Unified Bootloader (common files for version 2)

 

[BobhWasatch]

"Booting by EFI" doesn't mean "not grub". It can mean grub or it can mean systemd boot, depending on how your system was installed. You need to find out how your system is really booting.

 

[keeka]

The PVE host is setup for EFI only booting and I am using grub, not systemd boot.
Some time ago, I switched form `grub-pc` to `grub-efi-amd64`. As you can see, grub-pc was installed, then removed and its configuration remains.
So I was wondering:
Do I still need `grub-pc-bin`?
Can I purge `grub-pc`?

I know it may do no harm to retain unused binaries, but I wanted to a) understand and b) completely remove redundant packages.

 

[BobhWasatch]

Maybe you should have asked the question that way in the first place.

You only need the efi packages for booting with an EFI BIOS and you only need the pc packages for booting from legacy BIOS. You need the common packages for both. You normally only get one or the other set, your setup is an anomaly because you switched modes. Also, grub-pc and grub-efi-amd64 are metapackages that only contain dependencies (apt show <package> is your friend).

Examples (not PVE, plain Debian):

Legacy Machine:

ii  grub-common                                   2.06-13+deb12u1                      amd64        GRand Unified Bootloader (common files)
ii  grub-pc                                       2.06-13+deb12u1                      amd64        GRand Unified Bootloader, version 2 (PC/BIOS version)
ii  grub-pc-bin                                   2.06-13+deb12u1                      amd64        GRand Unified Bootloader, version 2 (PC/BIOS modules)
ii  grub2-common                                  2.06-13+deb12u1                      amd64        GRand Unified Bootloader (common files for version 2)

EFI Machine:

ii  grub-common                                   2.06-13+deb12u1                              amd64        GRand Unified Bootloader (common files)
ii  grub-efi-amd64                                2.06-13+deb12u1                              amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 version)
ii  grub-efi-amd64-bin                            2.06-13+deb12u1                              amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 modules)
ii  grub-efi-amd64-signed                         1+2.06+13+deb12u1                            amd64        GRand Unified Bootloader, version 2 (amd64 UEFI signed by Debian)
ii  grub2-common                                  2.06-13+deb12u1                              amd64        GRand Unified Bootloader (common files for version 2)

 

[keeka]

Thanks for that. The host was originally installed with PVE6. I don't recall the exact history, but I remember installing grub-efi-amd64 following the upgrade to PVE7. That process removed grub-pc.
IIRC if I then purged grub-pc and reran update-grub, I ended up with a non bootable system. I'm sketchy on the common dependencies of grub efi vs grub bios. The contents of those packages are minimal, but I'm guessing pre/post conf they do is significant in what I experienced. Just a bit confused!
So, do I still need `grub-pc-bin` & can I purge `grub-pc`? Or rather should I be able to purge `grub-pc` without any ill effects?

 

[BobhWasatch]

I have never purged grub-pc or grub-efi, but I would think it is ok to remove since it is just a dependency package and only exists to bring in other packages that it depends on. Configuration files should be in the common packages. To be sure maybe do "apt install --reinstall grub-efi" before running update-grub.

Or, leaving it alone won't hurt anything either...

 

[keeka]

To be sure maybe do "apt install --reinstall grub-efi" before running update-grub

That could be it! Thanks for the help.
I mean to look at the grub packages' pre/post install/remove scripts to see what they do in respect of running grub-install and update-grub.
I'm old enough to remember LILO and once had a stab at installing linux (unsuccessfully) on an hp ux machine (PALO).

Or, leaving it alone won't hurt anything either...

Yes, I know!

 

[keeka]

Those grub-pc and grub-efi-amd64 preinst, postinst, prerm, postrm scripts look pretty complex. I will put any OCD tidying up to one side on this occassion!