Why are there multiple file allocation tables in a FAT32 fil

Why are there multiple file allocation tables in a FAT32 file system?

Solution

-----FAT32 File System------:
FAT16 supports volumes up to 4 GB, whereas theoretically FAT32 can manage volumes up to 2 terabytes.
The FAT32 on-disk format and features on Windows 2000 are similar to those on Windows 95 OSR2 and Windows 98.

The size of a FAT32 cluster can range in size from 1 sector (512 bytes) to 64 sectors (32 KB), incremented in powers of 2.
Since FAT32 requires 4 bytes to store cluster values, many internal and on-disk data structures have been revised or expanded.
Most programs are unaffected by these changes; however, disk utilities which read the on-disk format must be updated to support FAT32.

The main difference between FAT16 and FAT32 is the logical partition size. FAT32 breaks the 2-GB logical drive limitation of FAT16 volumes by
extending a single logical drive capacity to at least 127 GB. If you have a 2-GB FAT16 drive, you must use a 32-KB cluster. With FAT32,
the range for a 4-KB cluster, for example, includes drive sizes between 512 MB and 8 GB.

The largest possible file for a FAT32 drive is 4 GB minus 2 bytes. FAT32 uses 4 bytes per cluster within the file allocation table.
This differs from FAT16, which uses 2 bytes per cluster within the file allocation table. Table 3.3 shows the default cluster sizes for FAT32.

A FAT32 volume must have at least 65,527 clusters. Also, the cluster size on a FAT32 volume cannot be such
that the file allocation table is greater than (16 MB – 64 KB)/4, or almost 4 million clusters.

FAT16 and FAT32 do not scale well. As the volume gets bigger, the file allocation table gets bigger,
which dramatically increases the amount of time it takes Windows 2000 to compute how much free space is on the boot volume when the system is restarted.For this reason, you may not create a FAT32 volume larger than 32 GB using the Format utility.