Disk cloning is the process of creating a 1-to-1 copy of a

hard disk drive 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 mag ...

(HDD) or

solid-state drive A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is a ...

(SSD), not just its files. Disk cloning may be used for upgrading a disk or replacing an aging disk with a fresh one. In this case, the clone can replace the original disk in its host computer. Disk cloning may also be used for disaster recovery or forensics. In the context of

backup software Backup software are computer programs used to perform a backup; they create supplementary exact copies of files, databases or entire computers. These programs may later use the supplementary copies to restore the original contents in the event of d ...

, disk cloning is very similar to disk imaging; in case of the latter, a 1-to-1 copy of a disk is created inside a disk image file. Disk cloning may be done with specialized cloning software, backup software, disk imaging software that has the necessary features, or specialized hardware.

Operating environment

A disk cloning program needs to be able to read even protected operating system files on the source disk, and must guarantee that the system is in a consistent state at the time of reading. It must also overwrite any operating system already present on the destination disk. To simplify these tasks, most disk cloning programs can run under an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

different from the native operating system of the host computer, for example,

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few o ...

or an equivalent such as

PC DOS PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * ...

DR-DOS DR-DOS (written as DR DOS, without a hyphen, in versions up to and including 6.0) is a disk operating system for IBM PC compatibles. Upon its introduction in 1988, it was the first DOS attempting to be compatible with IBM PC DOS and MS- ...

, or

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, whi ...

. The computer is booted from this operating system, the cloning program is loaded and copies the computer's file system. Many programs can clone a disk, or make an image, from within the running system, with special provision for copying open files; but an image cannot be restored onto the Windows System Drive under Windows. A disk cloning program must have device drivers or equivalent for all devices used. The manufacturers of some devices do not provide suitable drivers, so the manufacturers of disk cloning software must write their own drivers, or include device access functionality in some other way. This applies to tape drives, CD and DVD readers and writers, and USB and

FireWire IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...

drives. Cloning software contains its own TCP/IP stack for multicast transfer of data where required.

Image transfer

The simplest method of cloning a disk is to have both the source and destination disks present in the same machine, but this is often not possible. Disk cloning programs can link two computers by a parallel cable, or save and load images to an external USB drive or network drive. As disk images tend to be very large (usually a minimum of several hundred MB), performing several clones at a time puts excessive stress on a network. The solution is to use

multicast In computer networking, multicast is group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast should not be confused wi ...

technology. This allows a single image to be sent simultaneously to many machines without putting greater stress on the network than sending an image to a single machine.

Image manipulation

Although disk cloning programs are not primarily

backup In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", ...

programs, they are sometimes used as such. A key feature of a backup program is to allow the retrieval of individual files without needing to restore the entire backup. Disk cloning programs either provide a Windows Explorer-like program to browse image files and extract individual files from them, or allow an image file to be mounted as a read-only filesystem within Windows Explorer.

Cloning software

This table highlights the common capabilities of disk cloning software.

Notes

References

{{Reflist, 30em, refs= Clonezilla home page
(includes supported filesystems and other info)
/ref> {{Cite web, url=http://www.mondorescue.org/docs/mondorescue-howto.html, title = MondoRescue HOWTO {{cite web, title=Norton Ghost, url=http://us.norton.com/ghost, publisher=

Symantec Symantec may refer to: *An American consumer software company now known as Gen Digital Inc. *A brand of enterprise security software purchased by Broadcom Inc. Broadcom Inc. is an American designer, developer, manufacturer and global supplier ...

, access-date=15 December 2012 About ntfsclone
{{webarchive, url=https://web.archive.org/web/20080221173134/http://www.linux-ntfs.org/doku.php?id=ntfsclone , date=2008-02-21
{{webarchive, url=https://web.archive.org/web/20080706133848/http://man.linux-ntfs.org/ntfsclone.8.html , date=2008-07-06 {{Cite web , url=http://www.partimage.org/Main_Page , title=Partimage home page , access-date=2008-05-26 , archive-url=https://web.archive.org/web/20170208121536/http://www.partimage.org/Main_Page , archive-date=2017-02-08 , url-status=dead Partimage supported filesystems
/ref>
/ref> {{Cite web, url=http://www.partimage.org/Supported-Filesystems, title = Partimage - Supported filesystems Clone a drive or partition with IsoBuster, Managed or otherwise
/ref> IsoBuster 4.3 Release notes
/ref> IsoBuster 4.8 Release notes
/ref> Storage software Backup Utility software types

Operating environment

Image transfer

Image manipulation

Cloning software

See also

Notes

References