The value of the 
space_info
  object is determined as if by using POSIX 
statvfs
  to obtain a POSIX 
struct statvfs,
  and then multiplying its 
f_blocks, 
f_bfree,
  and 
f_bavail members by its 
f_frsize member,
  and assigning the results to the 
capacity, 
free,
  and 
available members respectively
.