Re: debootstrap: enable --merged-usr by default
I had a conversation with Marco about this at FOSDEM. I'm sorry to
say that I still don't understand why we would make this change.
The links provided do not explain what the benefits are. And there
are downsides.
One obvious downside is reduced testing of existing systems which have
filesystem layouts not easily compatible with "merged /usr" (or at
least, not compatible without wholesale moving of stuff about, which
seems like a risk which would need a substantial justification).
Another bad consequence is that some existing configurations that do
not, for whatever reason, mount /usr early, will be harder to set up.
One may argue (as Russ cogently does) that the distinction between
/usr and / cannot be coherently maintained as a distro-wide property
of software if we take into account all the realistic use cases. But
there are some traditional configurations where the distinction _can_
be maintained and we shouldn't break those things without a reason.
Also, I fear that unless we provide a straightforward way to retain
separate /usr, including an appropriate d-i command line option, we
will get further pushback and anger from traditionalists. We risk
reopening old wounds (see some of the less temperate responses earlier
in the thread Ansgar links to as [1]). If there are benefits of
changing the default arrangement of new installs, it would be worth
thinking how those benefits could be obtained without the damage to
our community (even if the objections are felt, by many people, to be
technically unsound).
Finally, I have to say that I think that this summary from Ansgar
is not really accurate:
> As mentioned earlier, I would like to see --merged-usr enabled by
> default for Debian Stretch. The last discussion on -devel@[1] was
> quite positive; I had some additional positive feedback on IRC.
...
> [1] <https://lists.debian.org/debian-devel/2016/09/msg00269.html>
That is a link to a message from Russ which mostly explains why
mounting /usr early (ie in the initramfs, by default) is a good idea.
That has now been implemented and has caused very little push-back.
But this bug report requests something entirely different: it is about
actually moving the contents of /bin into /usr/bin, etc.
It is also not fair to say that the discussion was "quite positive".
There was a good deal of opposition of various kinds, much of it
quite heated.
Thanks for your attention,
Ian.
--
Ian Jackson <ijackson@chiark.greenend.org.uk> These opinions are my own.
If I emailed you from an address @fyvzl.net or @evade.org.uk, that is
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