I also didn't do a fresh install for 6.6 to 6.7; it happened 
automatically overnight via yum-autoupdate.  I then had to downgrade the 
glibc rpms to revive some of our software that uses matlab.  It may be 
fortunate that autoupdates to 6.8 have been blocked by "Metadata file does 
not match checksum" in mirrors.  I've just changed "enabled=1" to 
"enabled=0" in /etc/yum.repos.d/sl6x.repo to allow continued upgrades of 
6.7 rpms without moving to 6.8.

Steven Yellin

On Sat, 16 Jul 2016, John Pilkington wrote:

> Now that SL 6.8 has been released, many packages in the sl6x-related repos 
> are shown as upgradeable, but the release announcement still includes the 
> warning that:
>
> There should be no expectation that a "yum" upgrade to SL 6.8 will work.
> A new install is the recommended method to move from "sl6rolling" and the 
> released SL 6.8.
>
> Does this still apply?  When I first saw it I assumed that it referred 
> specifically to the RCs, but it's still there, post-release.  I'm pretty sure 
> I didn't do a fresh install for 6.6 > 6.7
>
> Thanks,
>
> John Pilkington
>