At Wed, 06 Jul 2011 21:27:08 +0200 CentOS mailing list centos@centos.org wrote:
What is the best way to install CentOS 6? Is there an upgrade facility from CentOS-5.6? If so, how does this compare with a clean installation?
The rule of thumb is to always to a fresh clean installation when upgrading from a major version (eg 5.x to 6.x). Make a backup of your configuration files. Presumably, your /home and/or /var/www directories are on their own file systems -- this makes things easier, althogh for a production server environment, you really want to do a fresh install on a fresh 'machine' (or virtual host), and then migrate services and content, testing as you go.