Funny you should mention the clean-install method.  Over the years I 
learned to do just that, much preferring to migrate applications and 
custom admin scripts than deal with potential problems trying to upgrade 
from one major release to another.  In the long run it saves a lot of 
time and aggravation.

Your advice is excellent for anyone thinking of doing the same thing.

Oh, and in my last message I forgot to send sincere Kudos to Dag along 
with the others ... I feel like a kid in a candy store whenever I grok 
around his EL repos.  There are some really valuable goodies in there 
which I depend on and which I've never had problems with.  It takes a 
*lot* of work to pull all the bits and pieces together.  Thanks Dag!


On 05/15/2011 08:59 AM, Nico Kadel-Garcia wrote:
> On Sun, May 15, 2011 at 10:48 AM, Chuck Munro<[log in to unmask]>  wrote:
>
>> Now I'm beginning to think I might migrate many of my current CentOS
>> machines to SL as they come up for replacement or upgrade to v6.
>
> It should be fairly easy: the interwoven rhn bits from RHEL are
> already gracefully replaced in both OS's. But as someone who's done
> various migrations, I urge you to back up your old system and do clean
> rebuilds with SL 6, wherever possible. The reasons are individually
> small, but numerous. Clean new configuration files to work from, uid
> and gid numbering and memberships that match the latest specs rather
> than being inherited from a previous base install, the discarding of
> packages that used to fulfill dependencies but are no longer needed, a
> chance to review your partitioning and select ext4 for your
> filesystems, etc. all add up.