How To Create A Bootable Clone Of Your Mac Hard Drive

Mac’s come with a built in tool called “Disk Utility” which can be used to clone your Mac Hard Drive. The process of creating a bootable clone of your Mac Hard Drive is fairly simple, but before we get into the nitty gritty of  actually creating a bootable clone of your Mac Hard Drive, lets talk  a little about the reasons and advantages behind doing this.

1. Great Way To Have A Functional Backup Of  Your Entire System

By cloning your Mac Hard Drive, you are essentially creating a exact copy or backup of your entire Mac system, this includes Operating System files and the Users home directories. Not only that, since this is a exact copy of your Mac Hard Drive, you can even boot of the Clone Drive by simply having the Clone Drive plugged in and keeping the Options key pressed down during system boot-up.

2. Useful In Testing Applications And Trouble Shooting Issues

The Clone Drive can be used to test  new applications or software updates before actually installing it on the primary system. Also, in case of a system problem, you could boot of the Clone and identify if the problem is software or hardware related.

3. Ready To Go Replacement Of The Primary Hard Drive

In case of a Hard Drive failure or corruption, you could be crippled for hours or even days before the primary Drive could be fixed and data restored. Instead, you now could be immediately back in business by simply booting of the Clone Drive.

Using Disk Utility To Clone The Mac Hard Drive

Okay, now that we have discussed the reason behind cloning your Mac Hard Drive, lets actually see how to do it. Every Mac comes with a built-in tool called “Disk Utility” has mentioned earlier, this is what we will use to clone your Mac Hard Drive. You will also need an external Drive. Make sure that the external Hard Drive you are using for this purpose is equal to or larger than the used space on the source Hard Drive you plan to clone. Also, make sure to backup any data on the external Hard Drive, since all data on the Drive will be erased.

Now with your external Hard Drive plugged in and “Command” Key and “R” Key pressed down power-on your system. This will boot your system in Recovery mode. The reason you do this is, since you are cloning your OS partition you do not want anything from being changed on the source Hard Drive, booting your system in Recovery mode achieves this. Once in Recovery mode, Launch “Disk Utility”.

Once in “Disk Utility”, select the OS partition from the left hand pane, which is usually the first partition under the first Hard Drive in the list. Then, click the “Restore” tab on the right hand pane. Here you should see your OS partition already selected in the “Source” box.

disk utility clone 1

Next, select the target partition on your external Hard Drive, on which you want to create the clone, from the Left hand side pane and drag it to the “Destination” box. Once the target partition shows up in the “Destination” box, hit “Restore” and the cloning process will begin. Once complete you should have a fully bootable replica of your OS partition / Mac Hard Drive.

disk utility clone 2

Assumption: Please note, that this article assumes you have a Mac Hard Drive with a single partition / volume. In case you have multiple partitions on the source Hard Drive and want all partitions cloned, then make sure to partition the target Hard Drive to match the partition structure of the source Hard Drive. For help with partitioning see my article “Partitioning A Hard Drive On Mac Running OS X Lion“. Once you have created identical partition structure on the target Hard Drive, you can clone each partition / volume using the method described above. Except OS partition, all other partitions can be clone while logged into the system.

It’s as simple as that. If you want to boot into your new clone, simply have the external Hard Drive connected and keep the “Options” key presses down during boot-up and select the Clone. Also, in case you want to restore a specific file from the clone, you could always access it from “Finder”, just like you access any external Hard Drive. And in case you have an unfortunate event like a Hard Drive failure or corruption, simply reverse the above process to restore the Clone to a new Hard Drive.

Update (30th March 2013): This article has been modified for clarity  and to ensure accuracy.

Please see disclaimer.

About Vijay

I was introduced to Computers about 20 plus years ago and ever since then have been fascinated and obsessed with it. Since then, I have been ( and still am ) a Student, a Computer Technician, a Programmer, a Network Admin and currently work as a SAN Storage Administrator. I love exploring, tweaking and customizing different features of popular operating systems. When I am not on my computer ;), I love to travel, shop, read and hang out with my family and friends.


  1. Adison Ross says:

    I have created bootable clone of my Mac drive using software Stellar Drive Clone. One can clone Mac hard drive using third party tool which provides you bootable clone of your disk. I found this application easy and reliable for cloning Mac.

  2. Hey Vijay, I have read through all the questions and if I missed this one then I apologize for asking again but when I attempt to clone my hard drive I get the following message:

    “Restore Failure
    Recovery partition restores can only be done on GPT partition maps.”

    What am I doing wrong?
    Cheers, J

    • Hi Julia,

      Looks like the error message is complaining about partition map / table format incompatibility. Are you selecting the entire disk or are you selecting a specific partition?
      You should be doing the later when using Disk Utility. Also what type of partition map / table are you using on the source and target?

  3. Hello Vijay (and other users),

    A colleague of mine recommended that I periodically reinstall my OS in an effort to improve system efficiency, but I’m a bit confused on the particulars of the process. If I clone my drive on an external HDD then reinstall Mac OS how do I then restore all the info that’s in the cloned drive? How is this any different from restoring from a Time Machine backup? Are there dis/advantages to either choice? Is this even a viable operation when it comes to creating minor performance improvements?

    Mid 2009 MacBook Pro currently running 10.8.3.



    • Hi Darrell,

      Interesting recommendation :) true to an extent, but in my personal opinion not worth the hassle. I would instead run “top” from terminal and see what is actually consuming system resource.

      Cloning / restoring from Time Machine is not same as reinstalling the OS, since the prior mentioned method will only get your system back to exact current state.

      What is it that you are exactly trying to restore after reinstalling, data? If yes, do you have a separate Data partition?

      Cloning and Time Machine have a few difference depending on what you are trying to do. With cloning you can actually mount the Clone Drive and run off it, but the disadvantage is you cannot capture the changes you make after you made a Clone. Converse is true with Time Machine backup.

  4. George Kelsey says:

    I completed the transformation of my late 2011 MacBook Pro / 8GB memory / OSX ML with the installation of a Samsung 840 Series 500GB SSD. It amazingly fast. Had to download a Trim management program and it is working great. I going to install this same 840 Series 500GB into my MacPro 2,1 / 16GB memory / OSX Lion. OSX Lion, recovery, & my added software is only using 233.23 GB of 999.35GB available space on the HDD. What would be the partition space recommended for the SSD ? Leave it at 500 GB or split it ? I have 1TB HDD’s located in bay #2 & #3 for additional media storage.

    • I would leave it alone, since you already have 2 other drives in the system.

    • Wouter says:

      What kind of trim management are you using? I have been running a Samsung 930 in my early Macbook pro 2011 and I haven’t used it so far.

      • George Kelsey says:

        I did a ton of research before I did the install of the Samsung 840 SSD. What I found out, even though Apple has been using both Samsung & Sandisk SSD’s in their Mac’s. The factory installed SSD’s were the only ones to have active Trim. I noticed this after the Disk Utility copy to the SSD. Go to about this Mac & open the drop down information for the drive. 3rd party SSD’s will show Trim inactive. Thats were the software from comes in. Gives you the control of Trim on 3rd party SSD’s. I will display Trim active in the specs & prevents all the garbage build up on the drive as it should. There is another program available that offers other control options. I wrote it down , but have to find it.

  5. Jasmine says:

    Although Disk Utility is great application of Mac but it doesn’t give bootable clone. Inorder to ensure your drive safety one must create bootable clone of their drive using some third party application. Clone Mac drive is recommended especiallly during transfer of data from one drive to another or from one Mac to another.

    • Not true. You can definitely create a bootable clone using Disk Utility as shown in this article. The only problem is, if you have more than one partition you will need to repeat the process for every partition.

      But yes, there are other good third party alternatives which come with more options. I only recommend Disk Utility because it comes built in and is free :)

  6. George Kelsey says:

    Per the Apple support web site there is suppose to be a Apple Hardware Test tool installed on the MacPro HDD or on the OSX Lion install disk. To open the test tool Apple instructs to restart system & hold the D key before the gray startup screen. I’ve done this from a restart & a full shut down & restart & the tool does not appear. Goes directly to the main screen. Any advise ? Do they want an upper case D, does it really matter ? I wasn’t able to find anything the OSX Lion 10.7.5 disk or a download on the Apple web site. Very puzzled.

    MacPro 2,1 – 2x3GHz Quad-Core Intel Xeon – 16GB Memory – Maxtor 1TB HDD, WD Black 1TB HDD x2

    • Hi George, had never heard off this before. One of the many reasons I blog, the learning process is a two way street :) . Anyways, I found the below support article on the apple support site on how to use the hardware test tool. Hope it helps.

      Also, Will try the same on my machine and let you know how it goes.

  7. Hi Vijay, i had a mac book pro with lion on it. I used onyx to do some cleaner up but just before it start it says run start disk for issue. I did that it said ” backup as many data as possible and re-install Mac OS X”. when i tried to boot up after this message it wont boot up. It only start the os and run for a short time and shutdown.

    I discovered the hard drive is sick, will backing up into a new HDD fix the issue? I am scared some system files are already damaged and wont help cloning the drive. Any ideas?

    • Hi Samuel, I doubt cloning will help your situation especially if the OS has been corrupted.
      May I ask, what you trying to analyze with OnyX before you ran into the issue. Was your system fully functional before? Also, were you able to retrieve your data and back it up?

      In any case, you could try a few things,
      1. Make sure to recover your data first (personal files etc). You could boot off a Linux Live Boot CD and access your data, provided File Vault was not enabled.

      2. Once you have your data recovered, boot into recovery mode ( keeping CMD + R keys pressed down while booting) and run “Disk Repair” using Disk Utility. Once done, reboot and see if it works.

      3. Reinstall Mac OS and see if that helps.

      4. Replace your disk and reinstall Mac OS and restore your data.

      Also, as mentioned by one of our readers ( George ) in the previous comment, you could try analyzing your laptop using the Mac Testing Tool, before replacing your drive, to figure out if it is really a hardware issue.

  8. Hello, I have successfully cloned my hard drive and booted but there are problems like entering activation keys for some programs.
    While I dont know the reason why, I am guessing maybe its because the hard drive that the OS system was partitioned in the first place ? do I really need to have un-partitioned system hard drive for cloning to work??

    • Hi Atilla, Not sure why you are being prompted for a activation key, was the application activated on the source? Anyways, no you do not need to have a unpartitioned source drive for cloning to work. But if your drive is partitioned, you will have to clone each partition separately (Disk Utility limitation). However, yOu can find other third party softwares, which will let you clone the complete drive in a single shot.

  9. Excellent help. I was getting the error 254 message as Rob did and reading his question and your explanation I was able to get right back on track. Thanks!

  10. Great info, Vijay. Last year I received my brother’s mid 2009 MacBook Pro [2.53 Ghz Intel Core 2 Duo] running Mac OS X 10.5.8
    Not a complete fan of the latest operating system, and was hoping to clone my drive before installing ANY newer OS, to rely on if I dislike the newer. Decided now to upgrade my drive 233GB to a 1TB HDD, and my memory 4GB to 8GB. I’d like to clone to the 1TB, swap the drives, and keep my 233GB as my “backup”. I used to use Acronis when I had a PC, and opinions vary on disk utility, CarbonCopy, etc.
    Step by step (not too computer savvy lol), could you please suggest how and what I should do?
    Thank you

    • Hi Tariq, There are a couple of ways you can do it. But before I suggest anything, since I personally haven’t used OS X 10.5.8, can you let me know if you are able to boot into recovery mode (by using CMD + R key stroke while boot up) or do you have to use a recovery disk. Also, does either of the options have Disk Utility available in recovery mode?

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