If you have run out of disk space and you need to find what folder or directory is taking up an abnormal amount of space use the following command at the root level.
du -ms *
This command gives you the size of each file (in megabytes) housed in your current directory. Change directories into any directory that seems oversized and continue to do this until you have reached what you think may be the culprit.
At this point you will need a bit more detail of what file or folder is oversized so use the following command
This lists every directory recursively from where you are and prints its size to the screen. It is very detailed and verbose.
If the list is too detailed or you need to look through the list item by item you can always use
after the command and then read or print out the contents of filename.txt that you have just created.