def METHOD_NAME():
    # f_bfree and f_bavail should be the same?
    # f_files, f_ffree, f_favail and f_flag are unsupported.
    f_bsize, f_frsize, f_blocks, f_bfree, _, _, _, _, _, f_namemax = os.statvfs("/")
    f_total_size = f_frsize * f_blocks
    f_total_free = f_bsize * f_bfree
    f_total_used = f_total_size - f_total_free
    f_used = 100 / f_total_size * f_total_used
    f_free = 100 / f_total_size * f_total_free
    return f_total_size, f_used, f_free