df(1) - report file system disk space usage
Show information about the file system on which each FILE resides, or all file systems by default.
-a, --all
       include dummy file systems
-B, --block-size=SIZE
       scale sizes by SIZE before printing them.  E.g., `-BM' prints sizes in units of  1,048,576  bytes.
       See SIZE format below.
--total
       produce a grand total
-h, --human-readable
       print sizes in human readable format (e.g., 1K 234M 2G)
-H, --si
       likewise, but use powers of 1000 not 1024
-i, --inodes
       list inode information instead of block usage
-k     like --block-size=1K
-l, --local
       limit listing to local file systems
--no-sync
       do not invoke sync before getting usage info (default)
-P, --portability
       use the POSIX output format
--sync invoke sync before getting usage info
-t, --type=TYPE
       limit listing to file systems of type TYPE
-T, --print-type
       print file system type
-x, --exclude-type=TYPE
       limit listing to file systems not of type TYPE
-v     (ignored)
--help display this help and exit
--version
       output version information and exit