Hi Vinod,

On Thu, May 7, 2015, at 02:36 PM, Vinod Gupta wrote:
> CMS is one of about twenty Physics groups here in Princeton University. 
> We have our own Linux distribution based on RHEL with a few Princeton 
> specific home grown RPMs. The CMS group has been using SL. We are trying 
> to find a most practical way of providing a "SL" environment on top of 
> RHEL based Linux without having to change the base distribution for the 
> other 19 groups in the department. I guess Princeton is not the only 
> University that has and want to maintain their own Linux distribution.
> 
> Since both PU and SL are based on RHEL, I believe, there is lot more 
> similarity than differences in the two distributions. Can we simply 
> setup workstations of CMS group using PU linux and then install a few SL 
> RPMs to convert them to SL? Will it work for CMS work or there are some 
> fundamental changes which make SL very different, and probably 
> incompatible with RHEL?
> 
> Thanks,
> 
> Vinod Gupta
> Physics department
> Princeton University

It sounds like you're wanting to know how different SL is from RHEL. I'd
suggest taking a look at the SL Release Notes [0] that correspond to the
version(s) that you use to derive your PU distribution. The release
notes cover packages that are added to SL that aren't in upstream,
packages that are modified, and packages that are removed.

On the whole, I'd be very wary of mixing and matching repositories and /
or arbitrary packages, but if you decide that you can manage it, the
release notes should at least be a good starting point. Feel free to
follow-up with the list if you have other questions.

Also, thanks to the SL team for making it clear how they diverge from
upstream.  :)

Jim

[0]
http://ftp.scientificlinux.org/linux/scientific/7.0/x86_64/os/sl-release-notes.html