Disk cloning

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Disk cloning is the process of creating a 1-to-1 copy of a hard disk drive (HDD) or solid-state drive (SSD), not just its files.[1] 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.[1][2] Disk cloning may also be used for disaster recovery or forensics.[3] In the context of backup software, 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.[3][4]

Disk cloning may be done with specialized cloning software, backup software, disk imaging software that has the necessary features, or specialized hardware.[2][1][3]

Operating environment[edit]

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 different from the native operating system of the host computer, for example, MS-DOS or an equivalent such as PC DOS or DR-DOS, or Linux. 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 drives. Cloning software contains its own TCP/IP stack for multicast transfer of data where required.

Image transfer[edit]

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 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[edit]

Although disk cloning programs are not primarily backup 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[edit]

This table highlights the common capabilities of disk cloning software.

Name Operating system User interface Sector by sector[a] File by file[b] Hot transfer[c] Mount or extract[d] Operation model License
Standalone Client–server From a Live OS
Acronis Cyber Protect Home Office[5] Windows Graphical Yes[e] FAT32, NTFS, HFS+, APFS, ext2, ext3, ext4 and ReiserFS[6] Yes Yes Yes Yes Yes (64 MB) Trialware[f]
Apple Software Restore macOS Command-line Yes HFS+ No via hdiutil Yes Yes No Part of macOS
Clonezilla[7] Linux Text-based Yes FAT12, FAT16, FAT32, NTFS, ext2, ext3, ext4, reiserfs, reiser4, xfs, jfs, btrfs, f2fs, NILFS2, HFS+, UFS, minix, VMFS3 No Through a hack[8] Yes Yes (Clonezilla server edition) Yes (210 MB) GPL
dcfldd Linux Command-line Yes No No Yes Yes No ? GPL
dd (Unix) Unix Command-line Yes No No Yes[g] Yes No Yes[h] GPLv3
Disks (gnome-disk-utility) Linux Graphical UI only Part of Gnome
Disk Utility macOS Graphical Yes HFS+ Yes Yes Yes No Yes Part of macOS
EaseUS Partition Master[9] Windows Graphical Yes NTFS, ext4, ext3, ext2, FAT32, FAT16, FAT12, ReFS Yes Yes Yes Yes (Enterprise edition) Yes (526MB) Trialware
FSArchiver Linux Text-based No FAT32, btrfs, ext2, ext3, ext4, ReiserFS-4, HPFS, JFS, XFS ? ? Yes No ? GPL
Ghost[10] Windows Graphical,
Command-line
Yes FAT32, NTFS, HPFS, ext2, ext3[11] Yes Yes Yes Yes Yes Trialware
GParted Live CD[12] Linux Graphical No ext2, ext3 No No Yes No Yes GPL
Image for Windows[13] Windows Graphical Yes FAT32, NTFS, ext2, ext3 Yes Yes Yes No Yes Trialware
IsoBuster[14] Windows Graphical Yes FAT12, FAT16, FAT32, ExFAT, NTFS, ext2, ext3, ext4, MFS, HFS, HFS+, UDF, XFS,[15] ReFS[16] No Yes Yes No Yes Trialware
Kleo Bare Metal Backup Independent (Live OS) Graphical Yes FAT32, NTFS, ext2, ext3, HFS+ No ? No Yes Yes (570 MB) Freeware
Macrium Reflect Windows Graphical Yes ? No Yes No No Yes Separate Freeware and Trialware versions
Mondo Rescue[17] Linux Text-based Yes FAT32, NTFS, ext2, ext3 Yes ? Yes ? Yes *[i] GPL
ntfsclone[18][19] Linux Command-line No NTFS ? ? Yes No No[j] GPL
partimage[20][21] Linux Text-based No FAT32, ext2, ext3, ReiserFS-3, HPFS, JFS, XFS;
UFS (beta), HFS (beta), NTFS (experimental)[22]
? ? Yes Yes No[j] GPL
Partition-Saving[23] Windows, Linux, DOS Text-based
Command-line
Yes FAT32, NTFS, ext2, ext3 No Yes Yes No Yes Freeware
Redo Backup and Recovery Independent (Live OS) Graphical Yes FAT32, NTFS, ext2, ext3, ext4 No No No Can access networked drives Yes (225 MB) GPL

See also[edit]

Notes[edit]

  1. ^ Sector-by-sector transfer involves accessing the disk directly and copying the contents of each sector, thus accurately reproducing the layout of the source disk.
  2. ^ File-based transfer (as opposed to sector-by-sector transfer), involves opening all files and copying their contents, one by one. It requires the cloning utility to have a knowledge of the file systems on the source disk. The target disk's layout may not resemble that of the source disk.
  3. ^ Hot transfer refers to copying the contents of a volume on which there are open files in use. Implies use of shadow copy or a similar technique.
  4. ^ Extracting is the process of browsing a disk image and retrieving some of the files that it contains, at the user's discretion. Mounting a disk image is the process of making the disk image content available to the user as if he or she is accessing a physical read-only disk.
  5. ^ At the Disk Cloning mode, Sector by sector feature is automatically applied and it's the only one way.
  6. ^ At the trial version, you can't perform Disk Cloning feature via UI nor Rescue disc. Both methods are locked.
  7. ^ dd's clone images can be mounted as loop device.
  8. ^ There is no Live OS dedicated specially to dd. However Live CDs of various flavors of Linux should include dd as a part of coreutils. In general this applies also to Linux-based rescue CDs (although they may not provide dd explicitly as their primary tool, they still may give access to a shell which allows dd invocation).
  9. ^ There is no ready-to-use Live CD with this utility. It does come bundled with Mindi-Linux which is a small Linux distribution that can be used to create a customized Live CD.
  10. ^ a b There is no Live CD dedicated specially to this utility. However, it is present on several rescue CD's together with other software.

References[edit]

  1. ^ a b c Gordon, Whitson (4 September 2018). "How to Clone a Hard Drive". PC Magazine. Ziff Davis.
  2. ^ a b Martin, Jim (2 July 2019). "Upgrading to a new laptop or hard drive? These apps will clone the data from the old drive in next to no time". Tech Advisor. IDG.
  3. ^ a b c Hayes, Darren R. (2014). A Practical Guide to Computer Forensics Investigations. Pearson Education. pp. 86–87. ISBN 9780132756150.
  4. ^ Nikkel, Bruce (2016). Practical Forensic Imaging: Securing Digital Evidence with Linux Tools. No Starch Press. p. 219. ISBN 9781593278007.
  5. ^ Zhidkov, D. A., Kuligina, N. O., & Pavlycheva, T. N. (2020). METHODS AND PROBLEMS OF UPDATING THE MICROSOFT WINDOWS 7 OPERATING SYSTEM TO MICROSOFT WINDOWS 10 IN THE ENERGY ENTERPRISE. European Journal of Natural History, (6), 30-34.
  6. ^ Bate, Madeleine. "Acronis True Image Review 2021: Is the High Cost Worth It?" Website Planet, WebsitePlanet, 10 May 2021, https://www.websiteplanet.com/cloud-storage/acronis/.
  7. ^ Clonezilla home page (includes supported filesystems and other info)
  8. ^ "[ubuntu] How to Mount Clonezilla Images".
  9. ^ "EaseUS Partition Master home page". (includes system reqruirements and latest updates).{{cite web}}: CS1 maint: others (link)
  10. ^ "Norton Ghost". Symantec. Retrieved 15 December 2012.
  11. ^ "Ghost compatibility with various file systems". Archived from the original on 2017-01-31. Retrieved 2017-01-19.
  12. ^ "GParted Live CD". Retrieved 7 April 2013.
  13. ^ TeraByte Image for Windows home page
  14. ^ Clone a drive or partition with IsoBuster, Managed or otherwise
  15. ^ IsoBuster 4.3 Release notes
  16. ^ IsoBuster 4.8 Release notes
  17. ^ "MondoRescue HOWTO".
  18. ^ About ntfsclone Archived 2008-02-21 at the Wayback Machine
  19. ^ ntfsclone(8) man page Archived 2008-07-06 at the Wayback Machine
  20. ^ "Partimage home page". Archived from the original on 2017-02-08. Retrieved 2008-05-26.
  21. ^ Partimage supported filesystems
  22. ^ "Partimage - Supported filesystems".
  23. ^ Partition-Saving manual