Superblock

superblock is a record of the characteristics of a filesystem, including its size, the block size, the empty and the filled blocks and their respective counts, the size and location of the inode tables, the disk block map and usage information, and the size of the block groups

mkfs.ext4 /dev/vg01/lv01
mke2fs 1.44.1 (24-Mar-2018)
Creating filesystem with 2441850880 4k blocks and 305233920 inodes
Filesystem UUID: e6742357-a181-4b82-837f-9a01f3e52568
Superblock backups stored on blocks:
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
	4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
	102400000, 214990848, 512000000, 550731776, 644972544, 1934917632

Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done

• tune2fs -l /dev/VG_NAME/LV_NAME

mkfs.ext4 -S
-S  Write superblock and group descriptors only.

Aug 10 03:31:34 SERVER kernel: new mount options do not match the existing superblock, will be ignored

See also

• ext4 e2fsck, fsck.ext4, superblock, inode, block size, mkfs.ext4 tune2fs, wipefs, resize2fs stat, extents, Review ext4 journalctl logs. Read-only file system, virt-resize, ACL
• file, File system, directory, touch, mkdir, ls, ln truncate, fallocate, split, stat, inode, File descriptor, superblock, block size (blockdev), fuser, lsof, scrub, chattr, ulimit (nofiles), cp, mv, file (command), mkfifo, chmod