Every so often your hard drive runs out of space and you need to do a survey of what could be possibly be taking up so much space. The
du disk-usage command is great for that.
It can be noisy though as it traverses through all the directories and gives you a report on the size of each file. What we really want is just the size of each directory under the root dir.
du has a depth flag (-d) to help control the depth of directories that the command reports on.
du -h -d1 /
The above command gives you a report on all the directories and files at the top level.