Re: Alternate distributions

On Thu, 2004-04-29 at 18:00 -0700, alan wrote:
> On Fri, 30 Apr 2004, ted targosz wrote:
> 
> > I'd also like to thank Mark Gordon for his enlightening discussions in
> > other threads of this forum about the future of XD2 with regards to
> > various distributions.
> > 
> > I'm currently running XD2 on RH7.3 and have been delighted with it. 
> > However, RH7.3 is getting a bit long in the tooth and I'm starting to
> > look at SUSE and Fedora as possible alternates.
> > 
> > Fedora's FAQ suggests that XD2 should be uninstalled before an upgrade
> > is attempted.  I'm curious what is the best method to try to do an
> > uninstall of XD2?   Can I just fire up red carpet and uninstall a
> > particular set of packages?  Or should I just forget about that and do a
> > clean install of whatever new distribution I want to try?
> 
> A clean install is your best bet.
> 
> XD2 introduces a whole bunch of dependancy problems that are hard to 
> resolve.  (Since you are replacing huge quantities of libraries with 
> similar, but different named libraries, it is not all that surprising.)
> 
> It will also give you a chance to add in any of the new things that have 
> been added since 7.3.  (Quite a bit.)

While a clean install may be the easiest solution, I realize it's not
always ideal.

I feel like giving some tips on the process of uninstalling XD2.

- Start by backing up anything you care about.  This presumably
includes /home, possibly /root, possibly some files in /etc.  YMMV.
- Uninstalling Gnome while running Gnome isn't a terribly good idea.
Work from the console or KDE or vanilla X with twm or remotely via ssh.
- Many XD2 packages can be uninstalled without breaking anything.  Some
XD2 packages cannot be removed without breaking something.  A few XD2
packages cannot be removed without breaking something *critical*.

The following, for example, is a *bad* idea for XD2 users:
# rpm -qa | grep ximian | xargs rpm -e --nodeps # DO NOT RUN THIS!!!
This is because XD2 upgraded glib, a very basic library which was once
part of GTK+ and is now used by a many non-graphical programs.  PAM uses
it, for example, and if you break PAM, you won't be able to log in any
more.  That's the biggest issue.

The following at least *simplifies* the situation:
# for pkg in `rpm -qa | grep ximian`; do rpm -e --test $pkg > /dev/null 2>&1 && rpm -e $pkg; done
This removes all Ximian packages that don't satisfy dependencies of
other packages (assuming packages correctly report their dependencies).
The best part is that this command can be run repeatedly, with more
packages getting uninstalled at each iteration, up to a point.  Run it
enough times (until it's no longer uninstalling packages), and it will
have removed all the Ximian software that can be removed without causing
dependency problems for something in the main distribution.  

At this point, run "rpm -qa | grep ximian".  It may or may not be
necessary at this point to pipe it through less on the console; the list
should be pretty short at that point.  There shouldn't be any apps left,
only shared libraries and package bindings.  Now, since all those should
be provided as part of the base OS, it should be possible to downgrade
to the versions that came on the original install media.  This requires
using the --oldpackage flag with rpm -Uvh.  It may be necessary to
downgrade a number of packages atomically (i.e. downgrading multiple
packages at once), since bindings will depend on libraries that will
depend on lower-level libraries.

-Mark Gordon

_______________________________________________
Users maillist  -  [email protected]
http://lists.ximian.com/mailman/listinfo/users