40.3. File Systems

The df command reports the system's disk space usage. If you type the command df at a shell prompt, the output looks similar to the following:

Filesystem           1K-blocks      Used Available Use% Mounted on
                      11675568   6272120   4810348  57% /
/dev/sda1               100691      9281     86211  10% /boot
none                    322856         0    322856   0% /dev/shm

By default, this utility shows the partition size in 1 kilobyte blocks and the amount of used and available disk space in kilobytes. To view the information in megabytes and gigabytes, use the command df -h. The -h argument stands for human-readable format. The output looks similar to the following:

Filesystem            Size  Used Avail Use% Mounted on
                       12G  6.0G  4.6G  57% /
/dev/sda1              99M  9.1M   85M  10% /boot
none                  316M     0  316M   0% /dev/shm

In the list of mounted partitions, there is an entry for /dev/shm. This entry represents the system's virtual memory file system.

The du command displays the estimated amount of space being used by files in a directory. If you type du at a shell prompt, the disk usage for each of the subdirectories is displayed in a list. The grand total for the current directory and subdirectories are also shown as the last line in the list. If you do not want to see the totals for all the subdirectories, use the command du -hs to see only the grand total for the directory in human-readable format. Use the du --help command to see more options.

To view the system's partitions and disk space usage in a graphical format, use the GNOME System Monitor tab as shown in Figure 40-2, on the bottom of the tab under Devices.