root@ubuntu:~ # tune2fs -l /dev/sda1
 tune2fs 1.45.3 (14-Jul-2019)
 Filesystem volume name:   rootdisk
 Last mounted on:          /
 Filesystem UUID:          ef0ca1f8-28cf-4baf-ada6-f2271aaece17
 Filesystem magic number:  0xEF53
 Filesystem revision #:    1 (dynamic)
 Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent 64bit flex_bg sparse_super large_file huge_file dir_nlink extra_isize metadata_csum
 Filesystem flags:         signed_directory_hash
 Default mount options:    user_xattr acl
 Filesystem state:         clean
 Errors behavior:          Continue
 Filesystem OS type:       Linux
 Inode count:              4194304
 Block count:              16776704
 Reserved block count:     838835
 Free blocks:              14124456
 Free inodes:              3922963
 First block:              0
 Block size:               4096
 Fragment size:            4096
 Group descriptor size:    64
 Reserved GDT blocks:      1024
 Blocks per group:         32768
 Fragments per group:      32768
 Inodes per group:         8192
 Inode blocks per group:   512
 Flex block group size:    16
 Filesystem created:       Tue Nov 19 16:10:05 2019
 Last mount time:          Wed Feb 19 22:49:42 2020
 Last write time:          Wed Feb 19 23:57:02 2020
 Mount count:              7
 Maximum mount count:      -1
 Last checked:             Tue Nov 19 16:10:05 2019
 Check interval:           0 ()
 Lifetime writes:          10 GB
 Reserved blocks uid:      0 (user root)
 Reserved blocks gid:      0 (group root)
 First inode:              11
 Inode size:              256
 Required extra isize:     32
 Desired extra isize:      32
 Journal inode:            8
 First orphan inode:       2753990
 Default directory hash:   half_md4
 Directory Hash Seed:      10d55539-f000-4835-bafa-bc8d0a1c5b17
 Journal backup:           inode blocks
 Checksum type:            crc32c
 Checksum:                 0x421d487a