On Wed, 2005-07-27 at 07:29 -0600, gf wrote:
> Hi,
> I have read through the release documents, but am unclear about the
> following. Is it 'safe' to upgrade SL4.0 to SL4.1 through yum? Can I
> point yum to the 4.1 repositories and expect that the right thing will
> happen? If this will not work, what is the advisable method for
> upgrade?
> 
> Thanks for your help.
> 
> -g

The current 4.1 repository
ftp://ftp.scientificlinux.org/linux/scientific/41

is Scientific Linux  4.1 test(40rolling) Release Candidate 2 for i386
July 21, 2005.

You might want to wait to upgrade until the actual 4.1 is released.  In
particular this version does not have the recent security upgrades which
are in 4.0 (of course if your 4.0 is up to date, you already have them).
The final 4.1 is due soon.

However, the answer to your question is "yes, that is the way to
upgrade."  It is safe.  

To paraphrase the documentation:

   1.   rpm -Uvh
ftp://ftp.scientificlinux.org/linux/scientific/41/i386/SL/RPMS/yum-
conf-41-2.SL.noarch.rpm
   2. yum update yum
   3. yum upgrade

Check your /etc/yum.repos.d/sl*repo after step one.  The rpm may install
the repos as ".rpmnew".  

/etc/yurm.repos.d/sl.repo should look like

[main]
[sl-base]
name=SL 4 base
baseurl=ftp://ftp.scientificlinux.org/linux/scientific/41/$basearch/SL/RPMS/
enabled=1