Re: [gentoo-dev] [PATCH] use.desc: add global USE flag 'split-sbin'

[David Seifert]

On Wed, 2019-10-16 at 11:18 +0200, Jaco Kroon wrote:
> Hi,
>
> On 2019/10/15 19:34, David Seifert wrote:
> > On Tue, 2019-10-15 at 12:04 -0400, Mike Gilbert wrote:
> > > On Tue, Oct 15, 2019 at 12:02 PM Mike Gilbert <floppym@g.o
> > > >
> > > wrote:
> > > > On Tue, Oct 15, 2019 at 8:00 AM David Seifert <soap@g.o>
> > > > wrote:
> > > > > On Sun, 2019-10-13 at 12:33 -0400, Mike Gilbert wrote:
> > > > > > On Sat, Oct 12, 2019 at 1:52 PM David Seifert <
> > > > > > soap@g.o>
> > > > > > wrote:
> > > > > > > On Sat, 2019-10-12 at 19:01 +0200, Dennis Schridde wrote:
> > > > > > > > On Samstag, 12. Oktober 2019 18:02:28 CEST William
> > > > > > > > Hubbs
> > > > > > > > wrote:
> > > > > > > > > On Sat, Oct 12, 2019 at 01:11:49PM +0200, Michał
> > > > > > > > > Górny
> > > > > > > > > wrote:
> > > > > > > > > > On Sat, 2019-10-12 at 13:00 +0200, David Seifert
> > > > > > > > > > wrote:
> > > > > > > > > > > * Some distros have not just merged / and /usr,
> > > > > > > > > > > they
> > > > > > > > > > >
> > > > > > > > > > >   have also merged /usr/bin and /usr/sbin. By
> > > > > > > > > > > giving
> > > > > > > > > > >   users the choice of merging */bin and */sbin,
> > > > > > > > > > >   Gentoo follows suit.
> > > > > > > > > > What about the scenario when /bin has been merged
> > > > > > > > > > with
> > > > > > > > > > /usr/sbin
> > > > > > > > > > and /sbin with /usr/bin?  ;-P
> > > > > > > > > I also don't see the need for something like this.
> > > > > > > > > The
> > > > > > > > > idea of
> > > > > > > > > the
> > > > > > > > > /usr
> > > > > > > > > merge is to have all binaries available in one place,
> > > > > > > > > and
> > > > > > > > > there
> > > > > > > > > really
> > > > > > > > > is not a good justification for separating bin from
> > > > > > > > > sbin.
> > > > > > > > Do I read this correctly?  USE=-split-usr currently
> > > > > > > > means
> > > > > > > > that
> > > > > > > > /bin,
> > > > > > > > /sbin, /
> > > > > > > > usr/bin and /usr/sbin point to the same directory?
> > > > > > > >
> > > > > > > > If that is not the case, then I agree that users should
> > > > > > > > have the
> > > > > > > > possibility
> > > > > > > > to set it up like this and USE=-split-sbin should be
> > > > > > > > supported.
> > > > > > > >
> > > > > > > > --Dennis
> > > > > > > I agree, I wasn't aware that USE=-split-usr implies the
> > > > > > > complete 2-
> > > > > > > level (/usr and *sbin) merge. In that case, all of this
> > > > > > > is
> > > > > > > obsolete.
> > > > > > That was NOT my intention when I introduced the split-usr
> > > > > > USE
> > > > > > flag.
> > > > > >
> > > > > > For bin/sbin, I would prefer to drop any conflicting links
> > > > > > unconditionally. Do you have examples of scenarios where
> > > > > > this
> > > > > > is not
> > > > > > possible?
> > > > > >
> > > > > William has confirmed on IRC that USE=-split-usr performs the
> > > > > complete
> > > > > Fedora-esque /usr merge (which makes sense IMO).
> > > > William's opinion is not the only one that matters.
> > > Sorry, I guess you are referring to the behavior baselayout? That
> > > doesn't necessarily align with the global usage.
> > >
> > https://gitweb.gentoo.org/proj/baselayout.git/tree/Makefile#n93
> >
> > Clearly the usr-merge in baselayout intends to merge all these 4
> > directories. There is currently no option to merge /usr and / but
> > keep
> > /bin and /sbin separate, so the most parsimonious solution here is
> > to
> > assume that usr-merge semantics in Gentoo is about merging all 4
> > directories.
> >
> >
> For what it's worth.  All of my systems are installed with a fixed-
> size
> 512MB / with everything else (including /usr) on separate LVs.
>
> Whilst sbin vs bin is just a matter of what's available, to me it
> makes
> sense to keep these split.  To me it's always been logical to keep
> administrative type (root) tools under sbin, and stuff that's
> generally
> useful for users under bin.
>
> Keeping / and /usr split (or the ability to keep it split) is rather
> crucial for me.  It's for historic installations a matter of space
> constraints on /.  For new installations it's a matter of keeping /
> as
> small as possible in order to have a smallish bootable system which
> can
> be used for recovering the rest of the system, ideally without an
> initrd
> (which also works to an extent).
>
> Kind Regards,
> Jaco
>

For the umpteenth time time: nothing will change. You can keep your
(albeit broken) separate / and /usr partitions. *NOTHING* will change
for anyone. There are no plans to change the defaults. This is *MERELY*
about giving people the chance to opt in to the /usr-merge.

That said, the idea of using / as a "recovery" filesystem in general is
broken: 
https://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken/
And no, this is not systemd breaking your system, or Lennart, it's
distros and userlands not being careful to have things in / never
depend on things in /usr.