Disk cloning is the act of copying the contents of a computer's hard drive. The contents are typically saved as a disk image file and transferred to a storage medium, which could be another computer's hard drive or removable media such as a DVD or a USB drive.
Purposes of disk cloning include:
- System recovery, for example to return a hard drive to its original configuration after serious problems.
- Provisioning new computers before sale.
- As a "reboot and refresh" option for public computers.
- Recreating your system configuration on a new computer.
- To return a system to an original configuration with no personal data before selling or giving a computer away.
Backing up your entire drive: Cloning vs. imaging
Both cloning and imaging create an exact record of your drive or partition. I'm not just talking about the files, but the master boot record, allocation table, and everything else needed to boot and run your operating system.
This isn't necessary for protecting your data--a simple file backup will handle that job just fine. But should your hard drive crash or Windows become hopelessly corrupt, a clone or image backup can quickly get you back to work.
When you clone a drive, you copy everything on it onto another drive, so that the two are effectively identical. Normally, you would clone to an internal drive made external via a SATA/USB adapter or enclosure.
But imaging a drive is more like creating a great big .zip file (without the .zip extension). Image backup software copies everything on the drive into a single, compressed, but still very large file. You would probably save the image onto an external hard drive.
So what are the advantages of each?
Should your primary hard drive crash, a clone will get you up and running quickly. All you have to do is swap the drives.
On the other hand, if your drive crashes and you've backed it up to an image, you'd have to buy and install a new internal hard drive, boot from your backup program's emergency boot disc, and restore the drive's contents from the backup.
So why image? An image backup provides greater versatility when backing up. You can save several images onto one sufficiently large external hard drive, making it easier and more economical to save multiple versions of the same disk or back up multiple computers.
You can find several programs that can do these chores, including the backup tools in Windows 7 and 8. But I recommend Macrium Reflect Free, which is free for personal use. It's easy to use, can clone and image, and in my experience, is extremely reliable.