[CentOS] Re: Reboots -- LSB 2.1 Core Generic Section 8.5

Bryan J. Smith <b.j.smith@ieee.org>

thebs413 at earthlink.net
Thu Jun 2 19:27:38 UTC 2005


From: Rodrigo Barbosa <rodrigob at suespammers.org>
> There is nothing wrong with using X11 at runlevel 3. The only thing
> that can't be present is a display manager (KDM, XDM, GDM etc).

That's _exactly_ what I'm talking about.
Run-level 3 starts xdm.
Several Linux distros use 2 for multi-user, 3 for multi-user w/X.

Run-level 2 as multi-user w/o networking or w/o NFS was introduced
by Red Hat, and any Fedora-based (or RHL-based) distro uses it.

> If it is, it is wrong, and doesn't comply with the unix standard (don't
> remember exactly which, but I studied it when working for Conectiva).

First off, it's not "wrong."  Many distros established many different
standards well before any standardization efforts.  Even Linus admits
that he based many things off of SunOS 4.1 (retroactively Solaris 1)
and Solaris 2, and Solaris uses 2-3.

[ Remember, Solaris was the original GNU platform. ]

So in that regard, Debian is actually like Solaris in its use of 2-3,
instead of Fedora-based 3-5.

Secondly, you are referring to Linux Standards Base (LSB).
Specifically, Section 8.5 in the General Section of the latest revision:  
http://refspecs.freestandards.org/LSB_2.1.0/LSB-Core-generic/LSB-Core-generic.html#RUNLEVELS  

And even this latest version states:
"However, it is not required that LSB-compliant run-time environments
 use these run levels; the distribution-provided install_initd script may
 map the run levels specified below to whatever distribution-specified
 run levels are most appropriate."

It should also be noted that not even Fedora Core's init scripts are
fully LSB compliant, and Debian and SuSE do far better in many areas.

LSB even declares RPM as the package standard.  But at the same time,
one might remember why LSB came into existance -- to try to get 
standards across largely FC/RHL forks and other RPM distros.  As much
as it attempts to be platform agnostic, some of its standards are
heavily defaulting to RPM ones.

> The standard is there. If a distro chooses not to follow it,
> you can be very sure it will have acceptance problems.

Not nit-pick, but your statement was _exactly_:  
  "Also, run-levels are standarized, and should be the same on all
   unix-like platforms."

Not only is there _no_ standard for System-V platforms, but
pretty much LSB says even Linux distros can do what they want.

There is _no_ "run-level standard" for "unix-like platforms."

> When I have time later today (or tomorrow), I'll give out the
> standard I'm mentoning and will give you a proper reference.
> Sorry I can't provide it from the top of my head.

LSB 2.1 Core Generic Section 8.5.  Again, URL:  
http://refspecs.freestandards.org/LSB_2.1.0/LSB-Core-generic/LSB-Core-generic.html#RUNLEVELS  

Just to summarize, this thread was _not_ to "prove you wrong."
It was just a reminder that not only do Linux systems vary wildly,
but "UNIX-like" systems do as well and you should be careful
with assumptions.  ;->



--
Bryan J. Smith   mailto:b.j.smith at ieee.org




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