On every do-release-upgrade Ubuntu does a btrfs snapshot. What sounds like a good idea is quite annoying if you don't have enough disk space. The update requires the same amount of space as currently occupied by the OS. I have a separate system partition for the OS which means I can only use half of my disk space.
My question is, can I work around the automatic backup? Since I have a separate disk partition its easy for me to get my system going in case the upgrade fails. It would be nice to be able to force the upgrade. Any ideas?