On Wed, Dec 2, 2015 at 3:16 PM, Andrew Lutomirski <luto(a)mit.edu> wrote:
On Wed, Dec 2, 2015 at 11:54 AM, Josh Boyer
> On Wed, Dec 2, 2015 at 2:35 PM, Andrew Lutomirski <luto(a)mit.edu> wrote:
>> On Wed, Dec 2, 2015 at 9:50 AM, Josh Boyer <jwboyer(a)fedoraproject.org>
>>> And you would do that via a single command how? By wrapping it in an
>>> architecture/bootloader agnostic wrapper. Which is what grubby is.
>> But it's not. grubby does things like adding kernels and removing
>> kernels. grub2-mkconfig enumerates kernels and generates a config.
> Hm. Wait. I think there might be a terminology conflict here. Are
> you specifically referring to grubby the binary, or do you mean grubby
> the package? Because I was talking about the latter, as it contains
> new-kernel-pkg, etc.
I'm talking about grubby the binary and grubby the approach of
incrementally editing the config rather than regenerating it each
>>>> Frankly, I'd like to see Fedora move away from
grub2 even on x86. But I'd
>>>> also like to see grubby go away.
Could you elaborate on that grub2 part?
>>> Maybe you could start by listing the problems you have
>>> (and apparently grub2) instead of just saying get rid of it?
>> Fair enough. Two major problems come to mind:
>> 1. grubby puts the most recently-installed kernel on top.
>> grub2-mkconfig puts the highest version on top. In the cases where
>> they differ, I'd argue that the latter is better.
> That's a matter of preference. If I have a newer kernel version
> installed that doesn't actually work, I want the older kernel I _just_
> installed to be the default and top entry so my machine boots to
> something I can use. This happens often when people try rawhide -rcX
> kernels to test something.
> Fixing this might be better served by filing an RFE for grubby to
> change the preference order.
Or file an RFE for grub2 to have an option to use the file timestamps
instead of the version for the sort order.
That sounds reasonable.
>> 2 .If I want to edit boot options, grubby makes it
>> painful, and the directions are simply wrong. For example, my
>> /etc/grub2-efi.cfg says:
>> # DO NOT EDIT THIS FILE
>> # It is automatically generated by grub2-mkconfig using templates
>> # from /etc/grub.d and settings from /etc/default/grub
> TBH, I just edit /boot/EFI/efi/grub.cfg directly. It works fine.
I do that to. I find it to be extremely tedious and error prone. In
*shrug*. I guess we're going to disagree on that point, but that
isn't the end of the world.
comparison, managing /etc/default/grub on the Ubuntu servers I
maintain is a piece of work, works every time, and requires no thought
about exactly how many copies of the same thing I have to change. And
that file exists on Fedora, with the same contents, but uselessly,
unlike Ubuntu. Debian/Ubuntu's update-grub tool is wonderful, and
it's really quite simple:
exec grub-mkconfig -o /boot/grub/grub.cfg "$@"
Of course, the paths would be a bit different for Fedora.
I have no experience with other distros. That may be why I don't
understand the desire to rip everything up. However, even in thinking
about it some I can't see where I would personally care that much.
>> That's grossly misleading. It *was* automatically
generated, but it
>> is certainly not automatically generated on an ongoing basis. If I
>> change settings in /etc/default/grub, nothing happens. If I actually
>> want to change boot options, I have to either manually edit every
>> instance (or somehow, magically, the correct subset of copies) in
>> /etc/grub2-efi.cfg, which is a real pain and easy to screw up. Or I
>> can cross my fingers any try to figure out the right invocation to
>> just regenerate the whole thing (grub2-mkconfig >/etc/grub2-efi.cfg,
>> presumably). Assuming that such an incantation exists (which it does
>> these days!), one wonders why it's not happening automatically on
>> kernel upgrades.
> How often are you editing the boot options for _all_ installed
> kernels? I'm not questioning what you're saying, but my experience
> tends show people edit boot options for a single stanza which isn't
> all that arduous.
I generally update for all because I don't trust grubby to propagate
them if I don't or I edit for all because I'm sometimes fastidious.
If I only do one, it's because I'm lazy.
How funny! I only edit one because I'm lazy. Grubby propagates the
change to every kernel thereafter. Also, I'm not sure I'd blindly
want an option passed to all existing kernels. Quite often it is
something I'm trying that is new enough to only exist in certain
kernels, or a debug setting I only want on certain kernels. But your
point is certainly valid.
>> To the extent that I do it wrong and grub2-efi.cfg diverges
>> which is implied by /etc/default/grub, etc, we have a mess. This can
>> happen due to settings editing and presumably due to other things.
> This sounds like a documentation issue? You're looking at the files
> grub2 installs and trying to follow their advice, but the distro
> doesn't actually use any of that?
I still think this is an issue. It might be worth focusing on documentation.
>> In fact, looking more closely, there's already a
>> grub2-mkconfig doesn't emit LANG=en_US.UTF-8. The grubby-generated
>> config has LANG=en_US.UTF-8 on all entries except vmlinuz-0-rescue. I
>> would argue that that's a bug. If grubby went away or started using
>> grub2-mkconfig internally, this bug and all bugs like it would become
>> A more minor (from my POV) problem:
>> 3. More critical-path code. grub2-mkconfig must work for Anaconda to
>> work. ostree requires it, too. But grubby is a separate and
>> presumably rather more complicated codebase, and it needs to be kept
>> in sync for kernel upgrades to work, and those are also critical path.
> I have a hard time being convinced this is a problem given the number
> of releases we've done and the number of times it's been a problem in
> said releases.
Certainly the status quo seems to work for the most part, especially
if users don't do anything fancy.
But Fedora's approach really seems to be considerably more complicated
than what everyone else does, and Fedora also packages all the code
for the simpler approach already. Other than some people having a
preference for a different sort order (which could easily be added to
grub2-mkconfig), what's the benefit, if any, of Fedora's incremental
It leaves existing configs which are known to work alone and doesn't
blow them away if you happen to make a typo in /etc/grub.cfg or
whatever? Breaking a single kernel boot because of a typo is fine.
Making your machine unbootable because you regenerated an entire
config file with a typo just seems silly. Why would you want to
expose users to that?