Hard Disk : Making Efficient Use of Disk Space

If you have a large hard disk and want to use the FAT file system on all or most of the
disk, you can prevent wasted space by using several small FAT partitions.
All data on a FAT partition are stored in allocation units called clusters. Each cluster is
made up of a fixed number of disk sectors.
The FAT file system supports disk or partition sizes up to 2 GB, but only allows a
maximum of 65,525 clusters. Therefore, whatever the size of the hard disk or partition,
the number of sectors in one cluster must be large enough so that all available space can
be included within 65,525 clusters. The larger the available space, the larger the cluster
size must be.
However, using a large cluster size wastes disk space. Even if a data file (or the last
portion of a data file) is much smaller than the cluster size, the computer must still use a
complete cluster to store the data. The rest of the cluster space goes unused