Display the amount of free and used storage space on all mounted file systems.
df [options] [filesystem]
-a displays information for all file systems.
-i displays inode information (the disk is organized into inodes).
-T prints the type of file system.
-t type displays information about specified types of file systems only.
-x type excludes specified types of file systems from the output.
—help displays a Help message.
The df command shows the amount of free and used space on a specified file system. If you want to know how filled up all of your disks are, use the df command without any arguments. The df command then displays information about used and available storage space on all currently mounted file systems.