John Haggerty wrote:
> I'm pretty new to yum, so can anyone say whether there are any 
> subtleties to upgrading SL 4.0 or 4.1 to SL 4.2 using yum?  The nicely 
> detailed  "How To Upgrade To The Latest Release" can clearly be adapted 
> to this task, but are there any gotchas when you do that?


This one works OK for upgrading from 4.1 to 4.2:


1) yum update
2) yum clean all
3) rpm -Uvh 
ftp://ftp.scientificlinux.org/linux/scientific/42/i386/SL/RPMS/yum-conf-42-3.SL.noarch.rpm
4) yum update yum

[reboot]

5) yum upgrade
6) yum clean all

[reboot]


Replace the ftp URL to the corresponding one for upgrading to 4.1 from 4.0. I do not know 
if a direct upgrade can be done from 4.0 to 4.2.