Linux Mint 17.2 Rafaela has been released in its two traditional flavors, Cinnamon and MATE, but the developers did not publish any release notes yet.
Like Linux Mint 17 and Linux Mint 17.1, Linux Mint 17.2 Rafaela is based on Ubuntu 14.04 Trusty Tahr and uses latest generation desktop environments: Cinnamon 2.6 and MATE 1.10, but most likely, many Linux Mint-specific improvements have been implemented.
To upgrade from either Linux Mint 17 Qiana or Linux Mint 17.1 Rebecca to Linux Mint 17.2 Rafaela, follow the below instructions.
How to upgrade from Linux Mint 17 Qiana to Linux Mint 17.1 Rebecca:
First, backup to official sources, just in case, if something unexpected happens.
$ sudo cp /etc/apt/sources.list.d/official-package-repositories.list{,.bak}
OR, if you are not familiar with wildcards, do:
$ sudo cp /etc/apt/sources.list.d/official-package-repositories.list /etc/apt/sources.list.d/official-package-repositories.list.bak
Next, we have to replace qiana with rebecca, in the sources file. Instead of doing this by hand, taking the lines one by one, I will be using this sed oneliner:
$ sudo sed -i 's/qiana/rafaela/g' /etc/apt/sources.list.d/official-package-repositories.list
$ sudo sed -i 's/rebecca/rafaela/g' /etc/apt/sources.list.d/official-package-repositories.list
Now, in order to finish the upgrade process, we have to update the local repository index and perform a regular system upgrade:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
Revert the changes, only if the upgrade process does not finalize successfully:
Replace the modified sources list with the backup:
$ sudo rm /etc/apt/sources.list.d/official-package-repositories.list
$ sudo mv /etc/apt/sources.list.d/official-package-repositories.list.bak /etc/apt/sources.list.d/official-package-repositories.list
Upgrade the repository index and perform a system upgrade:
$ sudo apt-get update
$ sudo apt-get dist-upgrade