Re: Double Win!
FAT (File Allocation Table)
The FAT file system is used by DOS, Windows 3.x, and Windows 95 (in most installations). The FAT file system can also be used by Windows 98, Windows Me, Windows 2000, Windows NT, and OS/2.
The FAT file system is characterized by the use of a file allocation table (FAT) and clusters. The FAT is the heart of the file system; for safety, the FAT is duplicated to protect its data from accidental deletion or corruption. Clusters are the FAT system's smallest unit of data storage; one cluster consists of a fixed number of disk sectors. The FAT records which clusters are used, which are unused, and where files are located within the clusters.
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.
In general, large clusters tend to waste more space than small clusters. For more information on managing cluster size, click See Also on the Help toolbar.
The FAT file system also uses a root directory. This directory has a maximum allowable number of entries and must be located at a specific place on the disk or partition. OSs that use the FAT file system represent the root directory with the backward slash character (\), and initially display this directory at boot-up.
The root directory stores information about each sub-directory and file in the form of individual directory entries. For example, a file's directory entry holds information such as the filename, the size of the file, a date and time stamp that indicates when the file was last changed, the starting cluster number (which cluster holds the first portion of the file), and the file's attributes (for example, hidden, system, and so forth).
FAT 32 (File Allocation Table 32)
FAT32 is a file system that can be used by Windows 95 OEM Service Release 2 (version 4.00.950B), Windows 98, and Windows 2000. However, DOS, Windows 3.x, Windows NT 3.51/4.0, and earlier versions of Windows 95 cannot recognize FAT32, and are thus unable to boot from or use files on a FAT32 disk or partition.
FAT32 is an enhancement of the FAT file system and is based on 32-bit file allocation table entries, rather than the 16-bit entries used by the FAT system. As a result, FAT32 supports much larger disk or partition sizes (up to 2 terabytes).
The FAT32 file system uses smaller clusters than the FAT file system, has duplicate boot records, and features a root directory that can be any size and can be located anywhere on the disk or partition.
NTFS (New Technology File System)
The New Technology File System (NTFS) is accessible by Windows 2000 and Windows NT. NTFS is not recommended for use on disks less than 400 MB because it uses a great deal of space for system structures.
The central system structure of the NTFS file system is the master file table (MFT). NTFS keeps multiple copies of the critical portion of the MFT to protect against corruption and data loss.
Like FAT and FAT32, NTFS uses clusters to store data files; however, the size of the clusters is not dependent on the size of the disk or partition. A cluster size as small as 512 bytes can be specified, regardless of whether a partition is 500 MB or 5 GB. Using small clusters not only reduces the amount of wasted disk space, but also reduces file fragmentation, a condition where files are broken up over many noncontiguous clusters, resulting in slower file access. Because of its ability to use small clusters, NTFS provides good performance on large drives.
Finally, the NTFS file system supports hot fixing, a process through which bad sectors are automatically detected and marked so that they will not be used.
Copyright (c) 1994-2000 PowerQuest Corporation. All rights reserved.
 |  |
 |
