Talk:Upgrade a 4.x Installation using a newer ISO image
at first I thought that this article should be deleted. That procedure has not sense, the subscription is not necessary to upgrade, you can simply enable the pve-no-subscription repositories and you can upgrade easely. The enterprise repositories are necessary if you want to run the most stable and updated release, if you just want the most updated one, not tested as much as the enterprise one, just use the pve-no-subscription repos. It can be of some value if you really have to upgrade to 4.1 and you don't have internet connection, so I edited it, correcting the wrong statement about the impossibility of upgrade.