Disk-­cloning software, also known as disk-­imaging software, is a time­-saving program that creates a sector­-by­-sector, low­-level copy of an entire hard drive (or partition). Symantec Ghost and Acronis True Image are two well­-known examples, but there are a few dozen others to choose from.

What’s the Difference Between Disk-­Cloning Software and Backup Software?

Disk­-cloning software is primarily designed to save time, while backup software is designed to protect data files in case of a hard drive failure or other disaster. Also, backup software copies the contents of a drive at the file level, while disk­-cloning software makes copies at the bit level. Disk­-cloning programs can also provide some protection against data loss, but their main purpose is to capture a particular configuration of software and operating system. That snapshot can then be pushed out to another PC with similar hardware components (e.g., similar motherboard, similar processor) or to dozens, or even hundreds, of PCs.

Why Is Disk-Cloning Important, or...Six Ways Disk­-Cloning Software Can Make Your Life Easier

1. New computer staging and deployment: If you buy a batch of new computers and you want to install a specially configured, unique combination of software and operating system, cloning software can save you days, or even weeks, of duplicated effort. Install the operating system and the software on your “source” machine, tweak all the settings, and then let the cloning software do the rest. However, keep in mind that for this solution to work, your computers must have similar hardware components. The motherboard and the processor need to be identical or at least similar. The hard drive on the destination machine needs to be as large as or larger than the hard drive of the source computer. If the video card, network card, and so on aren’t identical, you may be able to work with a single image, but there’ll probably be some extra work involved.
2. Standardization: You’ll save yourself a lot of time and frustration by making sure your computers are as consistent as possible. When you use disk-cloning, you ensure that your computers are as close to identical as possible. If you do each installation and configuration individually, it’s almost guaranteed that each computer will be a little bit different. For more information, go to our section on Standardizing Your IT Infrastructure. Also be sure to check out our Guidelines for Disk-Cloning tool.
3. Restoration of your computer after it fails: You should be backing up critical files on a daily basis or even more frequently, but having a reliable data backup is only the beginning of the recovery process. Over months and years, you’ve probably installed several dozen pieces of software and tweaked the settings in a hundred different ways. It could take you days to return your crashed computer to its original state. If you have a recent snapshot (e.g., a recent disk image), you’ll be up and running in an hour or so.
4. Preventive maintenance and troubleshooting: Some libraries don’t wait for a complete hard drive failure. Instead, they use cloning software to fix relatively minor problems. The cloning process takes a few minutes to an hour, depending on the speed of your network, and you don’t have to watch it as it runs. Overall, it’s fairly predictable. On the other hand, you often have no idea how long it’ll take to repair a problem with somebody’s software. It could take minutes, or it could take days.
5. Training labs: Many libraries with training labs and public computers reimage these machines periodically to eliminate any developing problems, viruses, spyware, patron downloads, abandoned files, etc. Disk security programs, such as Windows Steady State, Clean Slate, or Deep Freeze, have the same effect, but they use less bandwidth and fewer server resources.
6. Migrations and hard drive upgrades: If you’re buying a new computer or putting a new hard drive into an existing computer, you can save your existing configuration to a disk image and then restore from that image. Bear in mind, however, that the greater the hardware differences between the two computers, the more trouble you’ll have with the migration if you use this technique.

Key Actions

Try to make your computers as consistent as possible. The more consistent and standard your hardware, the easier it is to implement a cloning procedure.

Stories from the Field

Well, I know Dell will actually take an image from us or make an image and do it there, but that's an extra charge. So when we got those 12 computers in, we took one and made it exactly the way we wanted to. And from that point, we took Ghost and made a ghost image from that. And we did those other machines in a day and a half. So we imaged 11 machines in less than nine hours. So it’s a pretty quick process that way. And if we had to do it by hand, one by one, it would take the three of us a good week to do those 12.

Jarvis Sims
Hall County Library System, GA

Honestly, too, we don’t spend a lot of time trying to figure out why something doesn’t work. We image everything, so if a desktop is down, we just image it, and it’s done in six minutes or whatever in our main building. If we do it over the [wide area network] WAN — I’m here at the main branch and let’s say I had to do one at Walton—it takes about 25 minutes. If there is some configuration issue, it’s just faster to reimage it.

Michelle Foster
Boone County Library, KY

And I do my best to make sure that I’ve tried every possible combination, and within minutes after I put it out, someone finds something I didn’t think of; but that’s okay. Once that machine is configured and running, and I know it works well, I create an image of that machine on a portable hard drive, and then I can just clone it. I just push that image out and apply that image to all the other machines. So right now, every morning, the computers in the lab are all identical — same image, same hardware — and that works really well. I spend a good amount of time getting one machine working, and then I just copy and paste it to the other machines. Initially I do each machine one at a time in my office, because that way, I can test the image to make sure it worked. Sometimes, something goes weird. But yes, if someone calls me up and says, ‘Gosh, number 12 in the lab is not happy,’ I can go into my network software and say reimage this machine and then tell them, ‘Go ahead and restart the machine.’ And when it restarts, it’ll image itself.

Matt Beckstrom
Lewis and Clark Library, MT

Further Resources

If you only buy a handful of computers every year, you could take what you get from the manufacturer, add all of your software and call it good. However, this doesn’t scale well. It can take hours to set up and configure all of your applications. And if you’re installing your own operating system as well, you’re looking at three or four additional hours. Exhausted by the tedious swapping of setup CDs, many mid­-sized and large libraries use disk-­cloning software to automate this process. If you would like to find out more about disk-cloning analysis, check out our Further Resources section.