I have been through this with a 15 GB partition, that means, the upgrade proceeded, but a disk space warning came. It mostly succeeded but I needed some technical experience to repair the booting.
Temporarily freeing as much space as possible on the old system is the message here. I am just providing some general ideas below.
19GB is quite a lot for a system partition (especially a 14.04), so if you managed to filled it may point to you not having a separate partition for home
.
- So first, if
/home
is on the system partition, will be to move all user data away and make sure the back-up of your user data is up to date. You will put these back after the upgrade. Hidden user configuration data mostly could remain as that not take very much space, with the exception of .thunderbird
and the configuration data of the browser, that may contain several MB of cache.
- Clear the cache of stored installation files, make your package database up to date and remove unused dependencies:
sudo apt-get update && sudo apt-get clean && sudo apt-get autoclean && sudo apt-get autoremove
. These will be downloaded and installed again when needed, but mostly, you will be downloading updated versions anyway.
- Then indeed, remove all old kernels: these require more than 300 MB each.
- Bring the size of log files down. Other log files can be removes with
sudo rm -v /var/log/*log*
. With a near full drive, you may be having megabytes of log files.
- Temporarily remove user applications (LibreOffice, Gimp, Thunderbird, extra browsers you installed, ...). These are easily reinstalled on the updated system.
- Again remove dependencies that are not anymore in use after having removed applications:
sudo apt-get autoremove
Check your progress with df -h /
This would allow you to gain several GB of free space, enough for an upgrade.