fdisk -l

device     Boot   Start     End Sectors  Size Id Type /dev/sdb1          2048 2099199 2097152    1G 83 Linux /dev/sdb2       2099200 6293503 4194304    2G 83 Linux **/dev/sdb3**       6293504 6293903     400  200K 83 Linux 

blkid /dev/sdb3

/dev/sdb3: UUID="96cac981-3764-474b-82fe-89efc5ec17be" TYPE="ext4" PARTUUID="81a3aca2-03" 

tune2fs /dev/sdb3 -l

tune2fs 1.42.13 (17-May-2015) Filesystem volume name:   <none> Last mounted on:          <not available> Filesystem UUID:          96cac981-3764-474b-82fe-89efc5ec17be Filesystem magic number:  0xEF53 Filesystem revision #:    1 (dynamic) Filesystem features:      ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags:         signed_directory_hash  Default mount options:    user_xattr acl Filesystem state:         clean Errors behavior:          Continue Filesystem OS type:       Linux Inode count:              32 Block count:              200 Reserved block count:     10 Free blocks:              177 Free inodes:              21 First block:              1 Block size:               1024 Fragment size:            1024 Blocks per group:         8192 Fragments per group:      8192 Inodes per group:         32 Inode blocks per group:   4 Flex block group size:    16 Filesystem created:       Sun Oct 30 20:41:15 2016 Last mount time:          n/a Last write time:          Sun Oct 30 20:41:15 2016 Mount count:              0 Maximum mount count:      -1 Last checked:             Sun Oct 30 20:41:15 2016 Check interval:           0 (<none>) Lifetime writes:          90 kB Reserved blocks uid:      0 (user root) Reserved blocks gid:      0 (group root) First inode:              11 Inode size:              128 Default directory hash:   half_md4 Directory Hash Seed:      83db19a5-4c95-418e-91f1-3acc3de261d9 

/dev/sdb3文件系统size为200K，但是（block sum size + inode sum size）1024B200+128B32>200K，请问这里怎么解释呢？