Bug#746577: closed by Michael Biebl <biebl at debian.org> (Re: Bug#746577: systemd-sysv: for upgrade safety, systemd-sysv and sysvinit-core must be coinstallable)

[Tollef Fog Heen]

]] Zack Weinberg 

> On 05/06/2014 08:08 AM, Tollef Fog Heen wrote:
> > ]] Zack Weinberg 
> > 
> >> On Mon, May 5, 2014 at 5:40 PM, Tollef Fog Heen <tfheen at err.no> wrote:
> >>> ]] Zack Weinberg
> >>>> Fundamentally what I want is a bulletproof procedure for reverting to
> >>>> sysvinit in case something goes wrong.
> >>>
> >>> Sounds like you're arguing that sysvinit-core should no longer ship
> >>> /sbin/init, then, so systemd-sysv doesn't have to conflict with it.
> >>
> >> Wouldn't that make the sysvinit implementation of /sbin/init
> >> completely unavailable?  This is an earnest question.  I do not have
> >> access to package contents right now.
> > 
> > No, to revert you'd boot with init=/sbin/sysvinit.
> 
> Ah, I understand now.  Yes, this + systemd-sysv and upstart *also* stop
> shipping /sbin/init (it becomes a symlink under control of the
> administrator) + documentation would be a satisfactory conclusion as far
> as I'm concerned.  If we were to also move 'reboot' and friends to a
> shared utilities package, that might make the systemd-sysv package
> unnecessary.

I don't see any reason for the symlink being removed from systemd-sysv.
After all, if you don't want that symlink, just use systemd, not -sysv.

If you for some reason insist on having systemd-sysv installed, but
/sbin/init pointing to something else, there's always dpkg-divert.  I
can't find any non-contrived reason to do that, though.

> Ideally, also, if systemd is installed on a system that is currently
> running sysvinit, that doesn't change what /sbin/init points to; the
> administrator has to do that as a separate operation.

That is how it is today.  If you want to change /sbin/init, you install
systemd-sysv.

I'm quite ok with what we're doing now: if you're installing something
that depends on systemd-sysv | systemd-shim, you get the new default
(systemd).  If you don't like the new default, you get to take positive
action to select what you would like to use instead.

[...]

> > I have still not seen any reason whatsoever for this to be a command
> > rather than just changing a configuration file.
> 
> I have no problem with that.  I suggested a command because I thought
> the switch might be more complicated than just changing what /sbin/init
> is symlinked to, but right now it looks to me like that should be enough.

Ok, good, then we're in agreement about that at least.

-- 
Tollef Fog Heen
UNIX is user friendly, it's just picky about who its friends are