Re: Backward and forward compatibility

[Jeff Johnson <jbj redhat com>]

On Wed, Aug 27, 2003 at 07:50:32PM +0300, Axel Thimm wrote:
> On Wed, Aug 27, 2003 at 11:49:36AM -0400, Jeff Johnson wrote:
> > >On Wed, Aug 27, 2003 at 10:11:21AM -0400, Jeff Johnson wrote:
> > > coming to speak of it what is the compatibility range for the rpm
> > > format? I.e. will RH7.3 deal well with rpm generated under RH9 or
> > > later?
> > 
> > The compatibility range for rpm format is quite large, 5+ years.
> > 
> > Content is narrower, prolly back to rpm-3.0.4 at least, farther if packaging
> > is tuned.
> 
> Great!
> 
> > Content interpretation is covered explicitly by tracking dependencies.
> > 
> > And all above doesn't matter, because you'll get bit by something like NPTL,
> > or gnome1 vs. gnome2, or python vs. python2 or a bug in rpm long before
> > the format breaks.
> 
> OK, of course that's true, but I only want to replace rpmbuild in
> RH9/8.0/7.3 with a single version. So, if I understand it correctly a
> RH7.3 system upgrade to rpm 4.2 generates valid rpm files (including
> signatures etc.) for legacy RH7.3 systems.
> 
> > > I'd like to have a single rpm version for different build
> > > environments, e.g. rpmbuild 4.2 for RH9, RH8.0 and RH7.3.
> > >
> > > In fact I am already building with 4.2 for all RH platforms, is there
> > > anything to fear?
> 
> Would 4.2.1 be a better candidate for consolidating rpm versions?

Your choice is not as simple as choosing a version of rpm, you need to
worry about what kernel and glibc are on the target systems.

This is NPTL/TLS/futex/O_DIRECT prolly more in action.

If not NPTL, you want rpm version compiled w/o --enable-posixmutexes,
that means prefer rpm-4.1.1 over rpm-4.2 on non-NPTL.

And I suspect you can use rpm-4.2 to build for all platforms, that is certainly
my intent, but look before you leap, please.

73 de Jeff

-- 
Jeff Johnson	ARS N3NPQ
jbj@redhat.com (jbj@jbj.org)
Chapel Hill, NC