Quoting "Kaplan, Andrew H." AHKAPLAN@PARTNERS.ORG:
Hi there --
I need to upgrade one of our systems from its current distribution, Fedora Core 7, to the most recent version distribution, release 5.4, of the CentOS operating system. Can I do an in-place upgrade of the operating system without any adverse side-effects? Are there any issues that I should be concerned with before proceeding? Thanks.
Err.. you cant just upgrade from fedora to centos. Take full backup and install centos and then just restore configurations from backup..
-- Eero, RHCE