On Tue, Jul 23, 2013 at 05:56:17PM -0700, Jeffrey Anderson wrote:
> On Tue, Jul 23, 2013 at 5:45 PM, Nico Kadel-Garcia <[log in to unmask]> wrote:
> 
> > the problem here is the switch from one OS, a CERN release, to an
> > actual Scientific Linux release. That..... can be an adventure. I've
> > done it for CentOS=>Scientific Linux, and for RHEL=>CentOS and
> > CentOS=>RHEL. It's nasty, and I don't recommend it unless you're
> > getting paid hourly.
> >
> 
> Actually that is not quite the problem  I was trying to upgrade from the
> CERN SL5 to the CERN SL6, and that apparently is not supported.  But
> neither is a vanilla SL5 to vanilla SL6.
> 


One way to think about this:

the difference between minor update (5.8->5.9) and major update (5.9->6.x)
is one that requires a full reinstall.

Why? There are too many incompatible changes and writing an foolproof automated
upgrade tool is significantly more difficult compared to a full reinstall.

In other words, if "yum update" could handle it, they would have named it "5.10", not "6.x".

And of course if you do not require a bulletproof automated tool and
if you do not mind ending up with a funny mongrel system,
you can do the update/upgrade manually, even live, even successfully -
there are enough reports of people who have done exactly that.


-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada