“I’d like to use Carbon Copy Cloner to duplicate a drive on my Mac, but I don’t want to keep the external drive mounted all the time. CCC says that it supports “Shell Scripts,” but I don’t know how to write them. Can you help?” – LP

If you’re not familiar with Carbon Copy Cloner (CCC), it’s a remarkable app for you Mac. Available for FREE, this app hosts a number of features, but really shines at making full, bootable, clones of your hard drive. It’s an invaluable tool for protecting your data, particularly if you aren’t backing up your Mac with Apple’s integrated TimeMachine.

CCC not only creates a bootable backup, but supports incremental backups and can be scheduled to your liking. Although it requires a little more setup and maintenance than TimeMachine, it’s a wonderful alternative or companion to your backup agenda.

While cloning your drive will be easy to setup with CCC, having it mount a drive on its own is not (internal or external). As you pointed out, CCC relies on “Shell Scripts” to extend it’s capabilities.

Shell scripts are simple applets that direct your computer at it’s core: the Unix command-line. Most users will never use the command line because it’s amazingly complex and requires a huge breadth of computer syntax to master. And, if you don’t really know what you are doing, using it can severely cripple or damage your operating system. It’s recommended that most users avoid poking around with it.

In this case, and although CCC can only execute shell scripts, I think we can build a better (and safer) solution using an AppleScript, CCC and iCal.

Here’s how to do it:

First, connect the backup drive to your Mac (either externally or internally) and be sure it’s powered ON. It should mount automatically, after a few seconds. Once it has , ensure that it is properly formatted. If you don’t know how to do this, check out my other tutorial, here.

Now, I’m assuming you have a copy of CCC downloaded and installed. If you don’t, grab it here.

CCC’s “scheduled task” feature also allows you to automatically “unmount” a drive once the backup is completed. As this reader has pointed out, mounting the drive for CCC is the trick.

Before we can write our AppleScript, we need to identify the backup drives specific “disk identifier number.” To do this, we’ll need to launch the Mac Disk Utility application: 

Click on the “Spotlight” (the magnifying glass) symbol in the upper left corner of your screen. Then begin to type “Disk Utility.” When you see the applications icon at the top of the listing, selected, press return to launch it.

When the app launches, you will see all the internal and mounted drives available to your computer on the left in the “source list.” Click on the drive you wish to use as your backup clone (making sure to click the “friendly name” of the drive, as opposed to the drive itself).

Next, go to the File Menu and choose “Get Info” (or press COMMAND+i). The next window will list details about this particular drive. Write down, or copy the “Drive Identifier” name (DI#). It’s case sensitive, so pay close attention to the number and letter combinations. In my case, the DI# is “disk6s1”. Once you have your DI#, you can quit the Mac Disk Utility Program.

It’s now time to write our AppleScript. Launch the AppleScript Editor (found in your Applications folder):

Click on the “Spotlight” (magnifying glass) symbol in the upper left corner of your screen. Then begin to type “AppleScript Editor.” When you see the applications icon at the top of the listing, selected, press return to launch it.

In the blank window, type the following:

do shell script "diskutil mount /dev/disk6s1"

You’ll want to substitute the DI# with your own.

Verify that the script doesn’t have typos by clicking the “Compile” icon in the toolbar.
If your syntax is correct, the text should reformat and you shouldn’t see any errors or receive any warnings.

To test the script, unmount your clone/backup drive (right-click and choose eject or drag the drive icon, on the desktop, to the trashcan in the dock. It will change into an “eject” symbol).

Once the drive is unmounted, go back to your AppleScript editor and click the “Run” button in the toolbar. Your clone/backup drive will mount on your desktop.

Now, let’s save.
Go to the File Menu, and Save (or press COMMAND+s).

Name the script appropriately, and save it somewhere safe: in my case, the Applications folder.

You may now Quit the AppleScript Editor.

Now, let’s open iCal (also in your Applications folder, but probably also in your dock). 

While your version of iCal may look slightly different (I’m using OS X.7, Lion), the setup and functionality is the same.

Decide on a time when you won’t actively be using your computer (likely) and the backup can perform without a hitch. In my case, I’m going to use 4am.

In iCal, create a new event by double-clicking on any day visible (I’m in week view, but this will work regardless of your view). Once the event is visible, double click again to edit the details of the event.

Mimic my details, adjusting frequency as you see fit. Under Alert, be sure to choose “Run Script” and navigate to the AppleScript that you previously created. When complete, click done. Now, whether iCal IS or ISN’T running, it will launch your script and mount your backup drive at the scheduled time.

Finally, we need to schedule the actual backup and unmount with CCC. Launch CCC (in your Applications folder):

Click on the “Spotlight” (magnifying glass) symbol in the upper left corner of your screen. Then begin to type “Carbon Copy Cloner.” When you see the applications icon at the top of the listing, selected, press return to launch it.

You will be prompted to select both the “Source” drive (in my case “MacHD”) and the “Destination” drive (in my case “MacHD_clone”).

Now, click the “Schedule this task” button in the lower right of the window. You will be warned that anything on the clone will be erased to make room for the bootable-backup. Since we reformatted this drive earlier, it isn’t a problem.

Clicking the “+” symbol, under the scheduled tasks pane, name your backup and fill out the details similarly to mine, adjusting frequency to match your earlier iCal setup.

Before saving, click the “Before and After” tab at the top. Adjust the “After copying files…”  >> “Destination” drop down to “Unmount the destination volume.” Now, save. You will be required to enter your administrator password.

You may now quit and close CCC.

That’s it! At 3:55a, daily, your connected drive will mount. At 4a, CCC will clone your drive and then unmount it!

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