On 12/15/2015 07:17 AM, Traiano Welcome wrote: > I see there is some attempt at an upgrade tool available, but it's > apparently broken: > https://wiki.centos.org/TipsAndTricks/CentOSUpgradeTool https://fedoraproject.org/wiki/Upgrading_Fedora_using_package_manager?rd=Upgrading_Fedora_using_yum Using "yum --releasever=7 distro-sync --downloadonly", then switching to single-user mode and "yum --releasever=7 distro-sync" you *might* be able to do it. However, you should test this on another system or in a virtual host. I've never done it, and it's highly likely to have problems. You should be aware that the purpose of the centos upgrade tool is to identify and warn the user about known problems with an upgrade. Because Anaconda installations are highly customizable, it's impossible for any of us to tell you if an upgrade will work. There are too many things that might not on your system, which we have no way of knowing. I don't know what keeps you from doing a clean install. Anything I can imagine that might convince you that this is a good idea, makes this a really bad idea. If you don't have backups, this is an extremely bad idea. If you're trying to minimize down time or work, this is an extremely bad idea.