I would like to upgrade a CentOS-6.5 home server to CentOS-7 on a new partition. What is the simplest way to achieve this? I would like to be able to boot into either version of CentOS until I am sure the new version is running OK.
Incidentally, I think most people today must have enough space on their hard drive to install a new OS on a new partition - it is surprising that this option never seems to be mentioned in upgrade documentation.