Displays disk space usage
df [options] [filesystem-list]
The df (disk free) utility reports on total and free space on each mounted device. By default, the report is in terms of 1-kilobyte blocks.
When you call df without an argument, it reports on the free space on each of the currently mounted devices.
The filesystem-list is an optional list of one or more pathnames that specify the filesystems you want a report on. The df utility permits you to refer to a mounted filesystem by its device pathname or by the pathname of the directory it is mounted on.
-t fstype Reports information only about the filesystems of type fstype, such as DOS or NFS.
-i Reports the number of inodes that are used and free ...