Ubuntu: Disk organize

$ sudo apt --installed list
$ sudo apt-get autoclean

$ sudo apt-get autoremove

$ sudo gem cleanup

$ sudo apt-get clean
$ dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs sudo apt-get -y purge

Ubuntu: 14.04 LTS -> 16.04 LTS

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade

---- challenge
$ sudo apt-get install update-manager-core
$ sudo do-release-upgrade