On Fri, 16 Nov 2018 05:11:01 -0500
Steve Litt <slitt@???> wrote:

> On Fri, 16 Nov 2018 22:11:17 +1300
> Daniel Reurich <daniel@???> wrote:
>
> > Hi Devuan followers, fans and friends,
> >
> > Debian as of the upcoming Buster release looks to be implementing a
> > merged /usr by default. At this stage there is no plan to make it
> > forced... but you never know what happens when their Technical
> > Committee suddenly decides it's an issue they need to force a
> > decision on...
> >
> > So... for Devuan, do we want to default to a merged /usr in our
> > coming release of Beowulf or are we going to resist another
> > pointless rearranging of the deck chairs...
> >
> > Keen to get some feedback on this
>
> Back in the what, 1970's, the Unix guys
> split /usr/sbin, /sbin, /usr/bin, and /bin to accommodate early boot,
> by separating out statically compiled stuff used in the earliest boot.
> But then initramfs made these separate directories unnecessary, so why
> in the world would we continue the split?
>
> Well, maybe because initramfs is a PITA many people choose to avoid.
> When things go wrong, it's the ultimate black box. And I'm very scared
> that one day Poettering/Redhat/Freedesktop.org will corner the market
> on initramfs makers, will make them systemd only, sans-systemd distros
> who have completed the merge will have the choice of backing out the
> merge or going to systemd.
>
> Initramfs (or initrd before it) is the ultimate black box. You can't
> get your normal voltmeter probes in there: You need to use special
> stuff that's hard to use. You can init the hard disk with /bin/bash,
> but not the initramfs. Oh, and not even the /bin/bash if the merge
> happens.
>
> Here's some info on dracut, the most prevalent initramfs maker:
>
> https://www.techradar.com/news/software/operating-systems/what-on-earth-is-dracut-1078647
>
> Oooh, notice they say dracut is "based on udev events". If you're
> avoiding systemd, and Redhat has taken over udev, what could
> *possibly* go wrong?
>
> Here's some recommended reading on "the merge":
>
> https://www.freedesktop.org/wiki/Software/systemd/InitrdInterface/
>
> https://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken/
>
> The gist of the preceding links is "hey, other programs conflate early
> with late boot programs, so don't blame us for doing it too. Oh, and
> by the way, most of those conflaters, like udev, are under our
> control. Conflation is another form of entanglement, but don't blame
> us."
>
> For those using ext4, assuming a kernel with ext4 compiled in, without
> need for root disk lvm, encryption, and raid, the init system can
> immediately use the static executables in /sbin to mount necessary
> disks and then go about the rest of the boot.
>
> Systemd loves to brag about their boot time, but on a system with ext4
> drivers compiled into the kernel, a separate /sbin guaranteed on the
> root partition, and minimal use of udev in the boot (you *could* run
> it as a daemon, in parallel, using runit), boots would be quick
> indeed. Switch-root, killall5, and all the other stuff done before
> disks begin to mount, goes away.
>
> I vote against "the merge".
>
> SteveT
>

So, after reading Steve's enlightening description, I am with him, the
merge is only needed by systemd and seems to be a way of forcing it on
everybody, so I am against it.

Rowland