TestDisk is a

free and open-source Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

data recovery In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The da ...

utility that helps users recover lost partitions or repair corrupted filesystems. TestDisk can collect detailed information about a corrupted drive, which can then be sent to a technician for further analysis. TestDisk supports

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicatio ...

Microsoft Windows Windows is a group of several Proprietary software, proprietary graphical user interface, graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, W ...

(i.e. NT 4.0,

2000 File:2000 Events Collage.png, From left, clockwise: Protests against Bush v. Gore after the 2000 United States presidential election; Heads of state meet for the Millennium Summit; The International Space Station in its infant form as seen fro ...

, XP, Server 2003,

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 ...

Vista Vista usually refers to a distant view. Vista may also refer to: Software *Windows Vista, the line of Microsoft Windows client operating systems released in 2006 and 2007 * VistA, (Veterans Health Information Systems and Technology Architecture) ...

Windows 7 Windows 7 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 July 22, 2009, and became generally available on October 22, ...

, Windows 8.1,

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 ...

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whic ...

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular o ...

NetBSD NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is ava ...

OpenBSD OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project empha ...

SunOS SunOS is a Unix-branded operating system developed by Sun Microsystems for their workstation and server computer systems. The ''SunOS'' name is usually only used to refer to versions 1.0 to 4.1.4, which were based on BSD, while versions 5.0 and ...

, and

MacOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of ...

. TestDisk handles non-partitioned and partitioned media. In particular, it recognizes the

GUID Partition Table The GUID Partition Table (GPT) is a standard for the layout of partition tables of a physical computer storage device, such as a hard disk drive or solid-state drive, using universally unique identifiers, which are also known as globally unique ...

(GPT), Apple partition map, PC/Intel BIOS partition tables, Sun Solaris slice and

Xbox Xbox is a video gaming brand created and owned by Microsoft. The brand consists of five video game consoles, as well as applications (games), streaming services, an online service by the name of Xbox network, and the development arm by the ...

fixed partitioning scheme. TestDisk uses a command line user interface. TestDisk can recover deleted files with 97% accuracy.

Features

TestDisk can recover deleted partitions, rebuild partition tables or rewrite the

master boot record A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of ...

(MBR).

Partition recovery

TestDisk retrieves the LBA size and CHS geometry of attached

data storage device Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are cons ...

s (i.e.

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magneti ...

memory card A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices. They allow adding memory to such devices using a card in a soc ...

USB flash drive A USB flash drive (also called a thumb drive) is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than . Since first ...

s, and

virtual disk Virtual disk and virtual drive are software components that emulate an actual disk storage device. Virtual disks and virtual drives are common components of virtual machines in hardware virtualization, but they are also widely used for various p ...

images) from the

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the b ...

or the

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 schedule tasks for efficient use of the system and may also ...

. The geometry information is required for a successful recovery. TestDisk reads sectors on the storage device to determine if the partition table or filesystem on it requires repair. TestDisk can perform deeper checks to locate partitions that have been deleted from a storage device or

disk image A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is usua ...

. However, it is up to the user to look over the list of possible partitions found by TestDisk and to select those that they wish to recover.

Filesystem repair

TestDisk can deal with some specific logical filesystem corruption.Jack Wiles, Kevin Cardwell, Anthony Reyes (2007). ''The best damn cybercrime and digital forensics book period'', page 373. Syngress. .

File recovery

When a file is deleted, the list of disk clusters occupied by the file is erased, marking those sectors available for use by other files created or modified thereafter. TestDisk can recover deleted files especially if the file was not fragmented and the clusters have not been reused.

Digital forensics

TestDisk can be used in

digital forensics Digital forensics (sometimes known as digital forensic science) is a branch of forensic science encompassing the recovery, investigation, examination and analysis of material found in digital devices, often in relation to mobile devices and comp ...

to retrieve partitions that were deleted long ago. It can mount various types of disk images including the Expert Witness File Format used by EnCase.Altheide, C., & Carvey, H. (2011). File System and Disk Analysis. In Digital Forensics with Open Source Tools. Elsevier. https://booksite.elsevier.com/samplechapters/9781597495868/Chapter_3.pdf Binary

s, such as those created with

ddrescue GNU ddrescue is a data recovery tool for disk drives, DVDs, CDs, and other digital storage media. It copies raw blocks of storage, such as disk sectors, from one device or file to another, while handling read errors in an intelligent manner to ...

can be read by TestDisk as though it were a storage device. In TestDisk versions prior to version 7, this feature could be exploited to inject malicious code into a running TestDisk application on Windows.

File system support

File system support for TestDisk is shown in the table:

References

{{Reflist

External links

TestDisk Wiki

List of news articles about TestDisk and PhotoRec

Data Recovery With TestDisk
Falko Timme, HowtoForge
Digital Forensics using Linux and Open Source Tools
Test Disk Team:
Main Contributor: Christophe Grenier. Location: Paris, France. URL: cgsecurity.org. He started the project in 1998 and is still the main developer. He is also responsible for the packaging of TestDisk & PhotoRec for DOS, Windows, Linux (generic version), MacOS X, and Fedora distribution. Cross-platform software Free data recovery software Free partitioning software Free software programmed in C Free system software Hard disk software Portable software Software using the GPL license