Unix and Linux df command

In Unix and Linux, the df command displays information about total space and available space on a file system

Flags

• -g Displays statistics in units of GB blocks. The output values for the file
  system statistics would be in floating point numbers as value of each unit in
  bytes is significantly high.

• -i Displays the number of free and used i-nodes for the file system; this output
  is the default when the specified file system is mounted.
• -I Displays information on the total number of blocks, the used space, the free
  space, the percentage of used space, and the mount point for the file system.
• -k Displays statistics in units of 1024-byte blocks.
• -m Displays statistics in units of MB blocks. The output values for the file
  system statistics would be in floating point numbers as value of each unit in
  bytes is significantly high.
• -M Displays the mount point information for the file system in the second
  column.
• -P Displays information on the file system in POSIX portable format.
• -s Gets file system statistics from the VFS specific file system helper instead
  of the statfs system call. Any arguments given when using the -s flag must be a
  JFS or Enhanced JFS filesystem mount point or device. The filesystem must also
  be listed in /etc/filesystems.
• -t Includes figures for total allocated space in the output.
• -v Displays all information for the specified file system.