The superblock stores much of the information about the file system, which includes the following:
Size and status of the file system
Label, which includes the file system name and volume name
Size of the file system logical block
Date and time of the last update
Cylinder group size
Number of data blocks in a cylinder group
Summary data block
File system state
Path name of the last mount point
Because the superblock contains critical data, multiple superblocks are made when the file system is created.
A summary information block is kept within the superblock. The summary information block is not replicated, but is grouped with the primary superblock, usually in cylinder group 0. The summary block records changes that take place as the file system is used. In addition, the summary block lists the number of inodes, directories, fragments, and storage blocks within the file system.