Mirror Image Backups

What are Mirror Image Backups?

Photo of paper people standing on a wood floor
© Westend61 / Getty Images

What is a Mirror Image Backup?

A backup program or online backup service that creates a mirror image backup is one that backs up everything on the computer, without reservation - including the installed software, personal files, registry, etc. - and consolidates it to just a few files.

Because of the size of mirror image backups, they are generally stored on external hard drives, network drives, or other internal drives, but sometimes DVD or BD discs are used.

The file type used for storing a mirror image backup is usually proprietary to the backup program that's being used, so they're different for each program. Sometimes no extension at all is used but that doesn't mean that it's not still custom to the program that was used.

A mirror image backup is not the same as a regular file backup or clone backup.

How Are Mirror Image Backups Different Than Regular Backups?

A regular backup is probably exactly what you think of when you think of backed up files - a few files, or a collection of folders with files in them, all backed up and ready to be restored, on demand, if and when you need them.

A clone backup is another type of backup some programs support. This type of backup takes everything from one drive and puts it on another drive. It's a clean copy from one hard drive to another, and is helpful if you have an extra drive lying around that you'd like to store your primary files on.

After creating a clone backup, you can just swap the cloned drive with your current one to have everything in place like you did at the time of the backup.

Like a clone, a mirror image backups also save absolutely everything that's on your computer at the time of the backup. This includes the operating system as a whole, including all of those important but hidden system files, plus all of your personal files, images, videos, documents, installed programs, temporary files...

even the files you might have sitting in the Recycle Bin.

Literally everything from the hard drive that you're backing up will be stored in the mirror image backup. And because the backup is stored in just a few files, you can keep them on an external hard drive that you're actively using, without compromising the backup files.

A mirror image backup is really the same thing as a clone backup but instead of copying the files to a different hard drive in a readily usable form, the files are backed up, and very often compressed as well, to a file, or a few files, that must then be restored using the original backup software.