I think once we get the packages with apt-get it stores in /var/cache/apt/archives . Is it safe to remove the archives files to save space? Can we remove other files as well to save some space?
I think it's safe to remove the archives files. So if you want to free up disk space this are my recommendations:
To delete downloaded packages (.deb) already installed (and no longer needed)
sudo apt-get clean
To remove all stored archives in your cache for packages that can not be downloaded anymore (thus packages that are no longer in the repository or that have a newer version in the repository).
sudo apt-get autoclean
To remove unnecessary packages (After uninstalling an app there could be packages you don't need anymore).
sudo apt-get autoremove
To delete old kernel versions
sudo apt-get remove --purge linux-image-X.X.XX-XX-generic
If you don't know which kernel version to remove
dpkg --get-selections | grep linux-image
And related at the clean cache... you can use this command
sudo dpkg --purge `COLUMNS=300 dpkg -l "*" | egrep "^rc" | cut -d\ -f3`
in order to delete all configuration related to unistalled program.
1) localepurge: for delete localizazion packages not interested for you
2) deporphan and his gnome interface gtkorphan.
You can run 'sudo apt-get clean' to clean out any cached .debs. If they're needed, they will be downloaded again. There's also a program called computer-janitor to help with removing old files.
If you messed around with installing partial packages then "apt-get autoclean" removes them too.
I run a Cron job to do this on some systems backed up to the Cloud to keep file sizes down.
According to this : http://www.howtogeek.com/howto/28502/how-to-free-up-a-lot-of-disk-space-on-ubuntu-linux-by-deleting-cached-package-files/ there is an option to disable caching in synaptic package manager...
Does anyone know where is the configuration being defined? (no where in /etc/apt/ as far as I can tell)