First, implement the code that similar to behave as the LBA of a drive.
sector:
The size is SECTOR_SIZE and is the minimum unit, call it with a LBA from 0.
cluster:
The size is SECTOR_SIZE * SECTORS_PER_CLUS and is the access unit, call it with a LBA from mini filesystem.
chunk:
This is one of each file distributed to “fsindex%04d.dat”.