There have been several file systems that have been released with the Windows operating system by Microsoft some of them were only improvements in previous file systems while some are based on an entirely different platform. There are two file systems that Windows uses for magnetic disks; FAT and NTFS.
We will have a look at both of them in this paper.FATFAT short for File Allocation Table is one of the earliest file systems supported by all versions of Microsoft Windows. Several versions have been released.FAT12The earliest version, assigned 12-bit values to cluster addresses which limited the cluster count to 4096 and a maximum volume size of 32 Mb. That’s the reason why it’s only used for very small partition/disks which are smaller than 16Mb such as Floppy Disks.FAT 16FAT 16 improved on some of the limitations of FAT12.
It supported volumes containing 65,536 clusters, cluster addresses could be 16 bit value. The maximum volume size could be 4 GB. It serves the purpose of small-medium disks or partitions.FAT 32Microsoft released FAT 32 with Windows 95(Release 2) to cater to the ever growing demands of high storage capacity devices.
It has 32 bits for storing clusters but 4 of those 32 bits are reserved technically leaving 28 bits for the cluster. Even these 28 bits are enough for the file system to handle around 268 million clusters. Theoretically speaking FAT 32 can handle 8TB volumes, but large cluster header sizes limit the use of FAT32 to 32GB disk partition/drives only. But FAT32 is still useful for larger disk partitions and drives when compared to its predecessors. (Microsoft, 2007)The general architecture of a FAT file system is usually the same with boot sector, file allocation table, a duplicate file allocation table, root directory and then any other data directory in sequence. The boot sector is also similar in all three versions.
(Microsoft, 2007)An issue with older versions of FAT was of long filenames; originally they only supported file names using the 8.3 format later Microsoft added support for long file names whereby the file system used a shortened version of the file name. FAT12 and FAT16 have limits to the size of the root directory (512 entries each one being 32 bytes in size) which presents a problem as it reduces the maximum number of files/directories that can be listed in the root. FAT32 however does not have this issue as there is no limitation on directory size plus it has the added flexibility that the directory can be located anywhere on a hard disk.NTFSLet’s look at the other major file system that the Windows OS makes use of NTFS. This file system organizes data in a completely different manner as compared to FAT file system.
The file system was launched initially to cater to the needs of complex high end interconnected system. Microsoft launched Windows NT 4.0 in 1996 and NTFS was its native OS. With the lines between complex networked computing requirements of a home and corporate user blurring, Microsoft shifted its focus on NTFS file system. This is reflected in NTFS being the native file system for all versions of windows after windows 2000. The support for FAT file system remains though.NTFS makes use of Logical Number Clusters which take up 64 bits.
The maximum possible volume size would then be 16Exabyte, but for practical purposes volume sizes are limited to lower figures. The NTFS partition typically contains Partition Boot sector, Master File Table, File system Data and a backup copy of the Master File Table.Apart from the capability to support very large disks/partitions efficiently (as compared to FAT) NTFS has several other advantages over FAT as well.In the area of data security as it has the capability of assigning access rights to files and folders. Different users can be given different rights.
Then disk quotas can also be assigned which limits the amount of drive/partition space a user can occupy. NTFS also has disk compression built-in which enhances the efficiency of storing large files. It also provides automatic encryption and decryption of data as it is read and written in order to secure it (NTFS.com, n.d)A major advantage of using NTFS is its recoverability.
As mentioned earlier NTFS is a log based file system. It keeps track of all the activities by marking pointers within the file tables; if any issue arises the system can be reverted to a state where it was stable. A backup copy of the Master File Table adds to the buffer against data loss.