Though it isn’t the recommended approach, I have ended up upgrading to Linux Mint 12 from Linux Mint 11 using an in situ route. Having attempted this before with a VirtualBox hosted installation, I am well aware of the possibility of things going wrong. Then, a full re-installation was needed to remedy the situation. With that in mind, I made a number of backups in the case of an emergency fresh installation of the latest release of Linux Mint. Apache and VirtualBox configuration files together with MySQL backups were put where they could be retrieved should that be required. The same applied to the list of installed packages on my system. So far, I haven’t needed to use these but there is no point in taking too many chances.
The first step in an in-situ Linux Mint upgrade is to edit /etc/apt/sources.list. In the repository location definitions, any reference to katya (11) was changed to lisa (for 12) and the same applied to any appearance of natty (Ubuntu 11.04) which needed to become oneiric (Ubuntu 11.10). With that done, it was time to issue the following command (all one line even if it is broken here):
sudo apt-get update && sudo apt-get upgrade && sudo apt-get
Once that had completed, it was time to add the new additions that come with Linux Mint 12 to my system using a combination of apt-get, aptitude and Synaptic; the process took a few cycles. GNOME already was in place from prior experimentation so there was no need to add this anew. However, I need to instate MGSE to gain the default Linux Mint customisations of GNOME 3. Along with that, I decided to add MATE, the fork of GNOME 2. That necessitated the removal of two old libraries (libgcr0 and libgpp11, if I remember correctly but it will tell you what is causing any conflict) using Synaptic. With MGSE and MATE in place, it was time to install LightDM and its Unity greeter to get the Linux Mint login screen. Using GDM wasn’t giving a very smooth visual experience and Ubuntu, the basis of Linux Mint, uses LightDM anyway. Even using the GTK greeter with LightDM produced a clunky login box in front of a garish screen. Configuration tweaks could have improved on this but it seems that using LightDM and Unity greeter is what gives the intended set up and experience.
With all of this complete, the system seemed to be running fine until the occasional desktop freeze occurred with Banshee running. Blaming that, I changed to Rhythmbox instead though that helped only marginally. While this might be blamed on how I did the upgraded my system, things seemed to have steadied themselves in the week since then. As a test, I had the music player going for a few hours and there was no problem. With the call for testing of an update to MATE a few days ago, it now looks as if there may have been bugs in the original release of Linux Mint 12. Daily updates have added new versions of MGSE and MATE so that may have something to do with the increase in stability. Even so, I haven’t discounted the possibility of needing to do a fresh installation of Linux Mint 12 just yet. However, if things continue as they are, then it won’t be needed and that’s an upheaval avoided should things go that way. That’s why in situ upgrades are attractive though rolling distros like Arch Linux (these words are being written on a system running this) and LMDE are moreso.