Comment 13 for bug 2024598

I couldn't find any difference between journal-4[12].txt that I was hoping for...

Next step is probably to reproduce the freeze, then log in via ssh and force the graphics processes (Xorg, gnome-shell) to crash by sending them a signal such as 'kill -ABRT pid'. That will produce a /var/crash/ file which you can then upload with 'ubuntu-bug' or 'apport-cli' and we can analyse what is freezing.