Ext2Fsd (short for Ext2 File System Driver) is a

free Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procur ...

Installable File System The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load drivers for file systems. History When IBM and Microsoft were co-developing OS ...

driver written in C for the

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

operating system family. It facilitates read and write access to the

ext2 The ext2 or second extended file system is a file system for the Linux kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed according to the same pr ...

ext3 ext3, or third extended filesystem, is a journaled file system that is commonly used by the Linux kernel. It used to be the default file system for many popular Linux distributions. Stephen Tweedie first revealed that he was working on extend ...

and

ext4 ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3. ext4 was initially a series of backward-compatible extensions to ext3, many of them originally developed by Cluster File Systems for ...

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...

s. The driver can be installed on

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Windows 8 Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012; it was subsequently made available for downl ...

Windows 10 Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on J ...

Windows Server 2008 Windows Server 2008 is the fourth release of the Windows Server operating system produced by Microsoft as part of the Windows NT family of the operating systems. It was released to manufacturing on February 4, 2008, and generally to retail on Fe ...

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. Support for

Windows NT Windows NT is a proprietary graphical operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems sc ...

was dropped in version 0.30. The program ''Ext2Mgr'' can optionally be installed additionally to manage drive letters and such. Since 2017 the application has effectively been abandonware as its author seemingly disappeared in August, 2020.

Reception

The German computer magazine

PC-WELT ''PC World'' (stylized as PCWorld) is a global computer magazine published monthly by IDG. Since 2013, it has been an online only publication. It offers advice on various aspects of PCs and related items, the Internet, and other personal tec ...

reported frequent program crashes in 2009. The program was not able to access ext3 partitions smoothly. This often led to a blue screen. Crashes of this type can lead to data loss, for example if there is not yet permanently stored data in the main memory. The program could only access ext2 partitions without errors. In 2012,

Computerwoche ''Computerworld'' (abbreviated as CW) is an ongoing decades old professional publication which in 2014 "went digital." Its audience is information technology (IT) and business technology professionals, and is available via a publication website ...

warned that access to ext3 partitions was "not harmless". Data loss may occur.

Features

Feature matrix

Supported Ext3/4 features

* flexible

inode The inode (index node) is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attribute ...

size: > 128 bytes, up to

block Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...

size * dir_index:

htree An HTree is a specialized tree data structure for directory indexing, similar to a B-tree. They are constant depth of either one or two levels, have a high fanout factor, use a hash of the filename, and do not require balancing. The HTree algor ...

directory index * filetype: extra file mode in dentry * large_file: > 4G files supported * sparse_super: super block backup in group descriptor * uninit_bg: fast fsck and group checksum * extent: full support with extending and shrinking. *

journal A journal, from the Old French ''journal'' (meaning "daily"), may refer to: *Bullet journal, a method of personal organization *Diary, a record of what happened over the course of a day or other period *Daybook, also known as a general journal, a ...

: only support replay for internal journal * flex_bg: first flexible metadata group * symlink and hardlink * Mount-as-user: specified uid/ gid supported

Unsupported Ext3/4 features

* 64BIT mode (to support 2^64 blocks) * journal: log-based operations, external journal *

Extended file attributes Extended file attributes are file system features that enable users to associate computer files with metadata not interpreted by the filesystem, whereas regular attributes have a purpose strictly defined by the filesystem (such as permissions or re ...

(EA),

Access control list In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on giv ...

(ACL) support

Features to be implemented in future

* Extents management improvement * EA and ACL security checking

Critical Bug

On November 2, 2017, a warning was issued with the release of version 0.69:

Don't use Ext2Fsd 0.68 or earlier versions with latest Ubuntu or Debian systems. Ext2Fsd 0.68 cannot process EXT4 with 64-BIT mode enabled, then it could corrupt your data. Very sorry for this disaster issue, I'm working on an improvement.

While it is not very clear whether v0.69 corrects this deficiency, users have reported that Windows 10 prompts them to format the ext4 drive even with the 0.69 version. The known solution is to convert the said ext4 drive to a 32 bit version.

References

External links

*
Old website
*{{SourceForge, ext2fsd, Ext2 File System Driver for Windows Free software programmed in C Utilities for Windows Windows disk file systems Free storage software