"Windows brought us a new file system called NTFS"

What they basically did was break up the single allocation of FAT.....into MEDIA Data tables.....having a portion of allocation management loaded to RAM resource depending on data being amended or created. They also added the attributes of security you mentioned, however, the principles are still the same type of allocation.....as data is created....so grows the allocation.

The same for a Unix type of structure, as data is created so grows allocation, as well as the pointer structures that pull data segments together....as this type of node structure does not implement link list where the above does in limiting some of the overhead.

doni