Is there a way to view a 'system size'? I want to know how large I should make partitions if I separate my /home from the / (root) partition, but I don't know how much space Ubuntu + every installed application takes up.
Essentially, the answer would be the total disk space taken if all home directories and user files were deleted. I've seen commands like these that show the size of different packages, but never one that creates a total. Perhaps one of these terminal commands could be modified to do such a thing?
http://www.commandlinefu.com/commands/view/3842/list-your-largest-installed-packages-on-debianubuntu