On Wed, Jun 25, 2014 at 1:13 PM, Lamar Owen <[log in to unmask]> wrote:
> On 06/25/2014 12:15 PM, James Fait wrote:
>>
>> Hi All:
>>
>> I recently received a new server system that has Centos 6.5 installed on
>> it.  I would like to change that to a Scientific Linux 6.5 system without
>> having to do a full reinstall, as this has no external media access except
>> for the network.
>>
>> Is is possible to do something like what is done for a minor version
>> upgrade, where I change what repos it is pointing to, and do a yum update to
>> get the differences.  Will this work?
>
> Yes, it will work partially. To make the switchover complete you need to do
> a 'yum distro-sync full' afterwards.  While I agree that a reinstall is
> cleaner, that isn't a direct answer to your question.

You also have to re-install *every single package*, especially those
that may have minor, uncertain differences between the two
repositories. It can be done, I've done it between CentOS and RHEL and
back several times on the same environment.

It's a very expensive process in terms of system resources and local
bandwidth. I *do* hope you have a nearby local mirror of Scientific
Linux you can use..

> I've done the other direction, from SLC (SL CERN) 5.4 to CentOS 5.5 and up
> while I was rebuilding CentOS 5 for IA64 last year.  There were a few
> outlying packages that I did need to deal with manually, but it's not really
> a big deal to switch from one to another.