Transaction-Safe FAT File System: Difference between revisions

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'''Transaction-Safe FAT File System''' ('''TFAT''') refersand '''Transaction-Safe Extended FAT File System''' ('''TexFAT''') refer to two [[file system]]s used in [[Microsoft]] products to provide transaction-safety for data stored on a disk. The goal is to reduce the risk of data loss in cases of power loss or unexpected removal of the drive. The latter problem has become more common with the spread of [[USB]] drives.

== {{anchor|FAT0|FAT1|TFAT12|TFAT16|TFAT32}}TFAT ==

== TFAT ==

The original''Transaction-Safe formFAT ofFile System'' (TFAT) of the '''TFAT12''', '''TFAT16''' and '''TFAT32''' file systems wasis a driver layer modification to the original [[File Allocation Table|FAT]] file systemsystems that[[FAT12]], [[FAT16]] and [[FAT32]] maintainedmaintaining two copies (FAT0FAT&nbsp;0 and FAT1FAT&nbsp;1) of the file allocation table instead of justtwo identical oneones. While performing a drive operation, changes would be made to FAT1FAT&nbsp;1. When the operation wasis complete, the FAT1FAT&nbsp;1 table would be copied to FAT0FAT&nbsp;0, updating the stable view of the file system.<ref name=MSTFAT>[http://msdn.microsoft.com/en-us/library/aa915463.aspx{{cite TFAT Overview]</ref>web

| url=https://msdn.microsoft.com/en-us/library/aa915463.aspx

| title=TFAT Overview

| date=2015-11-17

| publisher=[[Microsoft Developer Network]]

| access-date=2019-12-05}}</ref>

{{Details|Design of the FAT file system#CLUST 1}}

== TexFAT ==

The '''Transaction-Safe Extended FAT File System''' (TexFAT), TexFAT provides similar functionality to the original TFAT using the [[exFAT]] file system as the base file system instead of FAT. Introduced with [[Windows Embedded CE 6.0]], it replaced TFAT, and is frequentlysometimes referred to as ''TFAT'' as well, which can lead to confusion with the original TFAT described above.<ref name=MSTexFAT>[http{{cite web
| url=https://msdn.microsoft.com/en-us/library/cc907927.aspx
| title=Transaction-Safe Extended FAT File System]</ref>

| date=2010-03-18

| publisher=Microsoft Developer Network

| access-date=2019-12-05}}</ref>

The use of exFAT as the underlying file system allows for larger files and larger partitions. TexFAT requires a hardware-specific driver designed for the type of media on which the TexFAT volume resides.<ref name=MSTexFAT /> TexFAT is not supported by desktop/server versions of Windows.

== Limitations ==

Due to the lack of support in desktop [[operating system]]s, bothneither formsTFAT ofnor TFATTexFAT are not recommended for removable media. While the desktop OS could still read the drive, it could not use the transaction-safe features, so unexpected removal or a power outage could lead to data loss. In addition, directories created under the desktop OS may not be transaction-safe even if the drive is later attached to a TFAT/TexFAT aware OSoperating system.<ref name=MSTFAT />

== TFATSee also ==

* [[Design of the FAT file system]]

* [[Novell Transaction Tracking System]]

== References ==

{{reflist|2Reflist}}

== Further reading ==

* {{cite conference

| title=Design Methodologies of Transaction-Safe Cluster Allocations in TFAT File System for Embedded Storage Devices

| publisher=[[IEEE]]

| first1=Keshava

| last1=Munegowda

| first2=G.T.

| last2=Raju

| first3=Veera Manikandan

| last3=Raju

| first4=T.N.

| last4=Manjunath

| date=December 2014

| conference=2014 International Conference on Information Technology

| doi=10.1109/ICIT.2014.22}}

* {{cite conference

| title=Characterization of Transaction-Safe Cluster Allocation Strategies of TexFAT File System for Embedded Storage Devices

| first1=Keshava

| last1=Munegowda

| first2=G.T.

| last2=Raju

| first3=Veera Manikandan

| last3=Raju

| first4=T.N.

| last4=Manjunath

| date=2014-12-11

| conference=Computational Intelligence in Data Mining

| doi=10.1007/978-81-322-2205-7_47}}

{{File systems}}

[[Category:Windows disk file systems]]

[[Category:Flash file systems]]

[[zhCategory:TFATWindows CE]]