Monday, May 12, 2008

Diffrence between NTFS and FAT file system

Lets see what is the difftrence between NTFS and FAT file system.

In computing, a file system (often also written as filesystem) is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. File systems may use a data storage device such as a hard disk or CD-ROM and involve maintaining the physical location of the files, they might provide access to data on a file server by acting as clients for a network protocol (e.g., NFS, SMB, or 9P clients), or they may be virtual and exist only as an access method for virtual data (e.g., procfs).

FAT 32
Windows 95 OSR2, Windows 98, and Windows Me include an updated version of the FAT file system. This updated version is called FAT32. The FAT32 file system allows for a default cluster size as small as 4 KB, and includes support for EIDE hard disk sizes larger than 2 gigabytes (GB).

• FAT32 supports drives up to 2 terabytes in size. NOTE: Microsoft Windows 2000 only supports FAT32 partitions up to a size of 32 GB.
• FAT32 uses space more efficiently. FAT32 uses smaller clusters (that is, 4-KB clusters for drives up to 8 GB in size), resulting in 10 to 15 percent more efficient use of disk space relative to large FAT or FAT16 drives.
• FAT32 is more robust. FAT32 can relocate the root folder and use the backup copy of the file allocation table instead of the default copy. In addition, the boot record on FAT32 drives is expanded to include a backup copy of critical data structures. Therefore, FAT32 drives are less susceptible to a single point of failure than existing FAT16 drives.
• FAT32 is more flexible. The root folder on a FAT32 drive is an ordinary cluster chain, so it can be located anywhere on the drive. The previous limitations on the number of root folder entries no longer exist. In addition, file allocation table mirroring can be disabled, allowing a copy of the file allocation table other than the first one to be active. These features allow for dynamic resizing of FAT32 partitions. Note, however, that although the FAT32 design allows for this capability, it will not be implemented by Microsoft in the initial release.

Preferably, when using drives or partitions of over 200 MB the FAT file system should not be used. This is because as the size of the volume increases, performance with FAT will quickly decrease. It is not possible to set permissions on files that are FAT partitions. FAT partitions are limited in size to a maximum of 4 Gigabytes (GB) under Windows NT and 2 GB in MS-DOS. For additional information on this limitation, please see the following article in the Microsoft Knowledge Base:
ARTICLE-ID: 118335 (

TITLE: Maximum Partition Size in MS-DOS


NTFS is a high-performance and self-healing file system proprietary to Windows XP 2000 NT, which supports file-level security, compression and auditing. It also supports large volumes and powerful storage solution such as RAID. The most important new feature of NTFS is the ability to encrypt files and folders to protect your sensitive data
From a user's point of view, NTFS continues to organize files into directories, which, like HPFS, are sorted. However, unlike FAT or HPFS, there are no "special" objects on the disk and there is no dependence on the underlying hardware, such as 512 byte sectors. In addition, there are no special locations on the disk, such as FAT tables or HPFS Super Blocks.

The goals of NTFS are to provide:
• Reliability, which is especially desirable for high end systems and file servers
• A platform for added functionality
• Support POSIX requirements
• Removal of the limitations of the FAT and HPFS file systems
To ensure reliability of NTFS, three major areas were addressed: recoverability, removal of fatal single sector failures, and hot fixing. NTFS is a recoverable file system because it keeps track of transactions against the file system. When a CHKDSK is performed on FAT or HPFS, the consistency of pointers within the directory, allocation, and file tables is being checked. Under NTFS, a log of transactions against these components is maintained so that CHKDSK need only roll back transactions to the last commit point in order to recover consistency within the file system. Under FAT or HPFS, if a sector that is the location of one of the file system's special objects fails, then a single sector failure will occur.

NTFS avoids this in two ways: first, by not using special objects on the disk and tracking and protecting all objects that are on the disk. Secondly, under NTFS, multiple copies (the number depends on the volume size) of the Master File Table are kept.


NTFS is best for use on volumes of about 400 MB or more. This is because performance does not degrade under NTFS, as it does under FAT, with larger volume sizes. Disk quotas, file compression, file and folder level securities and more are other advantages.
Alternate data streams (ADS)
Sparse files
Reparse points
Volume mount points
Directory Junctions
Hierarchical Storage Management (HSM)
Native Structured Storage (NSS)
Volume Shadow Copy
File compression
Encrypting File System (EFS)
Symbolic links
Transactional NTFS


It is not recommended to use NTFS on a volume that is smaller than approximately 400 MB, because of the amount of space overhead involved in NTFS. This space overhead is in the form of NTFS system files that typically use at least 4 MB of drive space on a 100 MB partition. Currently, there is no file encryption built into NTFS. Therefore, someone can boot under MS-DOS, or another operating system, and use a low-level disk editing utility to view data stored on an NTFS volume. It is not possible to format a floppy disk with the NTFS file system; Windows NT formats all floppy disks with the FAT file system because the overhead involved in NTFS will not fit onto a floppy disk.

1) allows access local to w2k,w2k3,XP,win NT4 with SP4 & later may get access for somefile.
2) Maximum size of partition is 2 Terabytes & more.
3) Maximum File size is upto 16TB.4) File & folder Encryption is possible only in NTFS.

FAT 32
1) Fat 32 Allows access to win 95,98,win millenium,win2k,xp on local partition.
2) Maximum size of partition is up to 2 TB.
3) Maximum File size is up to 4 GB.
4) File & folder Encryption is not possible.


1 comment:

Pradeep said...

really I am very thank full to u.