The file system that Microsoft used 6 kinds to differ in the Communist Party of China of Dos/Windows set operating system (include to be about to be in the next version of Windows use Winfs) . They are respectively: FAt12, FAT16, FAT32, NTFS, NTFS5.0 and WINFS. We make an introduction to their relevant characteristic and regulation below one by one. Among them FAt12, FAT16, FAT32 all is Fat file system. It is the abbreviation of File Allocation Table.

The oldest file system FAT12:

This is to accompanying what Dos is born " old " file system. It uses list of 12 file allocation, get a name because of this. And system of the following FAT is in according to such means name. Use before in DOS3.0. But now, we still can search get this file system: Use at floppy disk driver. Of course, other place basically does not use this file system really. The disk capacity that Fat12 can manage is 8M. This is in at that time, below the circumstance that does not have hard disk, ability of this disk government is very big.

The limitation of Fat12 file system:

1) file name: Can be the file name of 8.3 formats only.
2) disk capacity: Most 8M. (× of 4096clusters × 4sectors/clusters 512bytes, Sectors)
3) file fragment is serious. (do not store on disk only inside discontinuous bunch. )

Use time is the longest the Fat16 of file system:

In the use process of Dos2.0, had appeared to the runs ability requirement of older disk, it is so in Dos3.0, microsoft rolled out new file system Fat16. Besides the divisional list that used 16 words to grow, fat16 and Fat12 are in other place exceeding likeness. Actually, grow as the word increase 4, the number of the cluster that can use increases to 65546. In total bunch number is in 4096 under when, of application still is the divisional watch of Fat12, when real need exceeds 4096 bunch, applied is the divisional watch of Fat16. The ability of the disk of government of Fat16 file system that just rolled out is 32M actually. This is in at that time is looking is enough big. 1987, the development of hard disk promoted the development of file system, the Fat16 after Dos4.0 can manage the disk of 128M. Next the development with this ceaseless number, arrive all the time 2G. Be in full in 10 years, the disk government ability of 2G is greatly over real need. What need points out is, in Windows95 system, used a kind of more distinctive technology, be called VFat to solve the problem such as long file name. FAT16 divisional format puts in serious defect: High capacity disk uses efficiency low. In the DOS of Microsoft and Windows series, the allocation of disk file is an unit with forming a cluster, a bunch allocates a file to use only, no matter this file takes up how many of whole bunch capacity. Such, although a very little file also wants to take up one forms a cluster, space of the rest bunch all and unused, create the waste of disk space. Because partition expresses the limitation of the capacity, what FAT16 partition founds is bigger, the size of every bunch on disk is larger also, the waste that creates thereby is bigger also. So, to solve this problem, microsoft rolled out FAT32 of a kind of brand-new disk partition format, provide support in Windows 95 OSR2 and version of the following Windows.
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