Editing Disk image (section)

== Limitations ==
Disk imaging is time consuming, the space requirements are high and reading from them can be slower than reading from the disk directly because of a performance overhead.<ref name=":1" /> 

Other limitations can be the lack of access to software required to read the contents of the image. For example, prior to Windows 8, third party software was required to mount disk images.<ref>{{cite web |date=30 August 2011 |title=Accessing data in ISO and VHD files |url=http://blogs.msdn.com/b/b8/archive/2011/08/30/accessing-data-in-iso-and-vhd-files.aspx |url-status=dead |archive-url=https://web.archive.org/web/20120419080359/http://blogs.msdn.com/b/b8/archive/2011/08/30/accessing-data-in-iso-and-vhd-files.aspx |archive-date=19 April 2012 |access-date=27 April 2012 |work=Building Windows 8 (TechNet Blogs) |publisher=Microsoft}}</ref><ref>{{cite web |title=Mount-DiskImage |url=https://learn.microsoft.com/en-us/powershell/module/storage/mount-diskimage |publisher=Microsoft}}</ref>  When imaging multiple computers with only minor differences, much data is duplicated unnecessarily, wasting space.<ref name=":1" />

=== Speed and failure ===
Disk imaging can be slow, especially for older storage devices. A typical 4.7 GB DVD can take an average of 18 minutes to duplicate.<ref name=":4" /> Floppy disks read and write much slower than hard disks. Therefore, despite their small size, it can take several minutes to copy a single disk. In some cases, disk imaging can fail due to bad sectors or physical wear and tear on the source device.<ref name=":10" /> Unix utilities (such as [[Dd (Unix)|dd]]) are not designed to cope with failures, causing the disk image creation process to fail.<ref name=":6" /> When [[data recovery]] is the end goal, it is instead recommended to use more specialised tools (such as [[ddrescue]]).