If you boot from the Scientific Linux cd with the "upgradeany" kernel boot option, you can upgrade CentOS to SL in-place. Afterwards, check for CentOS specific

If you boot from the Scientific Linux cd with the "upgradeany" kernel boot option, you can upgrade CentOS to SL in-place. Afterwards, check for CentOS specific packages with rpm -qa|grep -i centos, then check for problems with package-cleanup --problems, then merge changes with updatedb; locate rpmnew; locate rpmsave. If you yum upgrade shows you any problems exclude the problem package then run yum upgrade again. yum upgrade --exclude "nss" -y It's been pretty problem free for me so far.