[CentOS] Changing from RHEL to CentOS

Tue Jun 7 18:07:41 UTC 2011
Nicolas Ross <rossnick-lists at cybercat.ca>

> On Tuesday, June 07, 2011 10:30:18 AM Dvorkin, Asya wrote:
>> On Jun 7, 2011, at 9:49 AM, Lamar Owen wrote:
>> > On Tuesday, June 07, 2011 09:43:24 AM Nicolas Ross wrote:
>> >> I switch a RHEL machine in EL6 to scientific linux a while ago, and I
>> >> suppose it's the exact same thing for Centos.
>> > [snip process]
>
>> > You do realize that you didn't replace the RHEL binaries, right?
>
>> http://wiki.centos.org/HowTos/MigrationGuide
>
> While Phil's guide is a very good one for C5; however, the OP is asking
> about EL6, not 5.  EL5 doesn't have 'yum distro-sync' available; this is a
> seriously handy tool for this kind of migration.  EL6 does have 'yum
> distro-sync' available.
>
> There's a thread in the Scientific Linux Users mailing list on a similar
> topic; grep the archives for the subject "How to migrate yum installed on
> RHEL 6 to update from SL6 repository?" to get more information, especially
> on the need to replace all the upstream binary packages, not just the
> logos and the repository configs.

By looking at the man page, distro-sync wouldn't re-install a package with 
the same version. For exemple, on my rhel boxes, I have 
tzdata-2011g-1.el6.noarch installed, and on my sl6's one, I have 
tzdata-2011g-1.el6.noarch. It's the same exact version number. So the 
installed package wouldn't be re-installed.

You would need to do yum reinstall \* to properly re-install the package 
from the new repo (sl6 or c6 for instance).