Memory dump

from Wikipedia, the free encyclopedia

A dump or disk image (short dump , English image ) is a copy of the contents of a data carrier or data memory , which in a file can be saved. Hard disk , partition , floppy disk , CD / DVD or magnetic tape , for example , serve as data carriers or data storage devices .

technology

In contrast to a simple data backup , an image also contains information about the ( file system ) structure of the original data carrier (including the start sector ), since the raw data is read - including all meta and administrative  data - and not just the data of the files. This makes it possible to produce as accurate and complete copies of a data carrier as possible quickly. The high speed with which an image can be created results from the possibility of calling hardware functions directly in order to read or write the data. An image file reproduces the original disk very closely; In some cases, error information is also copied so that, for example, the image of a CD is not rendered unusable by copy protection mechanisms. Certain installed software will no longer be executed due to copy protection mechanisms if it is located in a different hard disk sector than during installation by simply copying back the program files. If you attempted to restore using a file-based backup, this software would no longer work.

If you want to duplicate CDs or initially equip several computers with the same programs or data, it can be advantageous to generate a corresponding CD or hard disk image and then write it several times. In this way, a computer can first be set up completely and its hard disk then “cloned” onto the hard disks of other computers.

The direct reference to hardware structures can, however, also prove to be a disadvantage - the image of a hard disk can usually not be written one-to-one to a CD, since the file systems of hard disks and CDs are usually completely different. In addition, image files can only be read with special programs on some operating systems and cannot always be changed; other operating systems contain functions for working with image files as an integral part.

CD image functions in particular are usually supplied with the operating system because the non-changeable ISO 9660 file system is very widespread. Occasionally there is talk of ISO images - this means images of CDs in ISO-9660 format.

Creation software

Windows

Windows from Microsoft , originally developed as an extension for DOS on the PC , was available as an operating system in the so-called MS-DOS line “ Windows 9x ” and currently in the Windows NT line.

macOS

The operating system for Apple computers (such as the Macintosh series) was called “Mac OS X” (versions 10.0 to 10.7) from 1998 to 2012, “OS X” (versions 10.8 to 10.11) from 2012 to 2016 and has been called “ macOS ” since 2016 "(From version 10.12). The classic Mac OS (until 2001) recently offered similar but largely incompatible options for memory images.

Unixoid

Under Unix-like operating systems refers Unix operating systems, while not Unix itself, but are therefore compatible with the majority, such as FreeBSD and GNU / Linux .

Other

See also

Web links

Wiktionary: Image  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Windows 7 instructions: Backup and system image with on-board resources - Netzwelt , March 29, 2016
  2. ↑ How do I burn an ISO file to CD / DVD? - UnSicherheitsBlog , January 9, 2009; u. a. Also with a description of the restoration, if the ( context menu ) selection “Burn data carrier image” has been overwritten by other applications
  3. ↑ Windows 7: Burn ISO files without additional software - Tipscout.de , February 6, 2016; u. a. with screenshot and selected Ubuntu image ( "Ubuntu8.iso" )
  4. ↑ Burn an ISO image to a DVD with CMD commands in Windows 8.1, 8 or Win 7/10? - SoftwareOK.de , June 25, 2015
  5. ↑ Burn an ISO image to physical DVD media with Windows 2008 R2 build-in tool “isoburn.exe” . (English) - Brad Chen's SQL Server Blog on MSDN , July 10, 2013
  6. ↑ Download Windows Resource Kit Tools (English) - Technlg , on February 8, 2010; both applications (ie cdburn[.exe]and dvdburn[.exe]) with timestamp April 18, 2003; these were probably later removed in the WRKTs and so by the u. a. isoburn[.exe]Replaced from Windows 7 supplied