Re: [gentoo-dev] rfc: locations of binaries and separate /usr

[Lars Wendler]

Am Freitag 06 Januar 2012, 17:07:20 schrieb Alex Alexander:
> On Fri, Jan 06, 2012 at 08:35:32AM -0500, Rich Freeman wrote:
> > On Thu, Jan 5, 2012 at 5:36 PM, Alex Alexander <wired@g.o> wrote:
> > > If people are really interested in keeping a tight, self contained
> > > root, we need to:
> > >
> > > - establish a [tight] list of software we consider critical for /
> > > - fix/patch software in that list so it can run without /usr there
> > > - create /bin => /usr/bin/ symlinks for above software (simplifies
> > >  things if packages start hardcoding /usr/bin here and there)
> > > - move everything else in /usr/bin/
> >
> > You're missing one thing:
> >
> > - establish a list of all the configurations that will actually work
> > with this self-contained root
> >
> > I think this is why there is so much disagreement over whether this is
> > a good move.  If you have a really simple configuration, then the
> > self-contained root concept works reasonably well (though apparently
> > we'll have to heavily patch newer versions of udev or abandon it to
> > sustain this).
> >
> > However, if you have a very complex configuration the current
> > self-contained root is already broken and you need an initramfs
> > anyway.  For in-between cases things might work now but that is likely
> > to change as upstream moves on.
> >
> > The binary distros don't have users tweaking their kernels and init
> > scripts, so they basically have to design for worst-case.  Gentoo can
> > get away with designing for more of an average case since we just tell
> > anybody with a complex case to go read a howto and configure what is
> > necessary (and we like to do that stuff anyway).
> >
> > We can choose not to like it, but it sounds like maintaining a
> > self-contained root for even the typical case will become untenable.
> > Those who argue that having /usr on a separate partition simply
> > shouldn't be supported are basically just saying that our
> > "self-contained root" should include everything in /usr which seems to
> > defeat the whole point of a "self-contained root" anyway.
> >
> > It seems to me that the most reasonable approach is to not force the
> > issue, but not deviate greatly from upstream either.  That means
> > accepting that over time the rootfs will become less and less capable
> > of working on its own, and immediately improving tools like dracut to
> > overcome these limitations.  Users who can get away with it can avoid
> > using an initramfs, at least for a time.
> >
> > Sure, it is all open source, and Gentoo can swim upstream if we REALLY
> > want to.  However, this only works if developers are willing to spend
> > the time constantly fixing upstream's tools.  It sounds to me like the
> > maintainers of packages like udev/systemd/etc want to actually move in
> > the same direction as upstream so in practice I don't see that
> > happening.
> >
> > Now, Gentoo is about choice, so one thing we should try to do as much
> > as possible is understand the limitations of the various
> > configurations and make it clear to users when they do and don't need
> > an initramfs.  To be honest, tight coupling worries me more than the
> > /usr move, since that has a lot more potential to constrain the
> > choices we can offer our users (which is a great deal of the value
> > that Gentoo offers).  I understand its advantages, but it seems
> > somewhat contrary to "the unix way."
>
> That's why I wrote "tight list". I do not expect the self-contained root
> to be able to handle everything /usr (or a complete initramfs) would.
> What it could and couldn't do is something that needs to be decided, but
> some work is already done there - it's just a bit messy and incomplete
> and because most people don't care it keeps getting worse.
>
> The important thing here is to make a clear definition of where we draw
> the line and make sure things work the way we want them to.
>
> I agree with you in that at some point patching may become too time
> consuming, but I still believe that if we do this properly, with a
> well-defined plan and list of packages we want to keep in / (with
> symlinks to be compatible with whatever others are trying to do), we
> won't be alone in this. Gentoo may be one of the most hardcore
> power-user distros out there, but we're certainly not the only one.
>
> Now, if only we had people interested enough in doing this... :)

I'm interested in everything which prevents such kind of insanity from Gentoo. 
So count me in as volunteer keeping /bin, /sbin and /lib in Gentoo and systemd 
away from it. 
As long as we keep trying and working hard I'm sure we can do the workload 
that might come across when blind upstreams start adopting those foolish 
systemd/GnomeOS ideas...

-- 
Lars Wendler (Polynomial-C)