Re: [ptxdist] /usr merge

[Ladislav Michl <ladis@linux-mips.org>]

On Wed, Apr 12, 2017 at 11:24:35AM +0200, Michael Olbrich wrote:
> On Wed, Apr 12, 2017 at 10:27:30AM +0200, Enrico Weigelt, metux IT consult wrote:
> > On 11.04.2017 12:07, Michael Olbrich wrote:
> > > I've just pushed a large series of commits for /usr merge. This means that
> > > /bin, /sbin and /lib are now symlinks to the corresponding directories in
> > > /usr. All files are installed accordingly.
> > 
> > Just curious: what's the actual problem to solve ?
> 
> The issues below.
> 
> > For my embedded projects, I haven't had an actual usecase for having
> > them separated, but on server systems lots of them over the past 20yrs.
> > 
> > Note that this separation indeed has serious reaons: separating the
> > base system (IOW: everything required to boot up at least to single
> > user mode and mount /usr - whereever it might come from). Most of the
> > practical usecases might be obsolete now (eg. storage is so cheap that
> > people rarely have the need to share /usr within clusters, etc), but
> > still there're lots of systems out there relying on that (maybe quite
> > irrelevant to ptxdist, but certainly for standard like Debian)
> > 
> > I'm personally agnostic to that, but I've already seen such setups
> > (eg. having /usr on separate SDcard) in embedded systems. So, it seems
> > better if that remains configurable.

That's also seen on many consumer electronic devices, but given poor
quality (hack until it works and then it's done), I wouldn't take it
as any measure.

Btw, this is quite a nice summary:
http://lists.busybox.net/pipermail/busybox/2010-December/074114.html

[snip]
> > I really have a bad feeling about such magic in existing commands,
> > which now suddenly change semantics.
> 
> That depends on your definition of changed semantics. After all, the files
> are still reachable at the specified path.
> 
> > At least that should be configurable.
> 
> Doing that is a lot of work. Because that only makes sense, if a separate
> /usr _really_ works. And that is more than making the recent changes
> optional. It starts with making sure that nothing outside /usr needs
> anything in /usr and continues with a clear concept of what should be
> possible without /usr mounted.
> I certainly don't have the time to do the initial work or maintain this
> longterm.
> 
> We have quite a few contributors that add new packages and keep packages up
> to date. But I'm the only one that actually works on the core stuff.
> So unless someone steps up to do this including the maintenance, it's not
> going to happen.

...and also does not need to happen ;-)
Anyway (and back to more constructive note), I updated and tested all my five
configurations and didn't find any issues. Nice work!

Thanks,
	ladis

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