Analyzing disk usage

We've spent a great deal of time in this chapter going over how to access media and mount storage devices. However, it's also important to understand how to manage that data and know how to determine how the space is being used. Finding the amount of free space on a volume couldn't be simpler. In Cinnamon, if you open the storage device in Nemo, you'll see the amount of free space on that volume shown at the bottom of the window. If you're working from a terminal window, the following command does the trick:

df -h

The df command will show you a list of volumes and the amount of free space available on each one. (The df command stands for disk free and the -h flag tells df that we want human readable output or rather shows the size of the disk in megabytes/gigabytes.) This certainly is useful information but not exactly what we want if we need to find out what is taking up all the space on a drive. For example, if a production server is running out of space, you would...