What is a disk image?
A disk image is a file that contains the file structure and contents of a storage device such as a CD-ROM, DVD, or hard drive partition. Disk images are frequently used to create exact duplicates of volumes. They are especially useful for producing boot disks and software installation media. On some systems (e.g., all versions of Mac OS X) it is possible to mount a disk image, allowing you to access its contents as if it were a normal (though typically read-only) volume.
There are many different disk image formats, and with the exception of
those that are self-mounting, you will most likely need a separate
utility to view and copy their contents or create new images. For
example, either Disk Copy or StuffIt Expander
5.0+ are required to access most Mac OS disk image
files. In Mac OS X, you can easily create disk images using Disk
Utility, which is located in
/Applications/Utilities. OS X handles the
.dmg format natively; if you need to mount a disk image
of a different format, try using Disk Utility or an application such
as Toast
Titanium. For Windows computers, Ghost is a commonly used program
for creating a disk image.
Also see:
Last modified on January 16, 2007.
