How To Create A Bootable Clone Of Your Mac Hard Drive

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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.


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About Vijay

Computer junky for 20 plus years and still obsessed with it. I enjoy exploring and tweaking popular operating systems and tinkering with computer hardware. Professionally, I work as a Storage Systems Administrator. When 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?

  11. Fantastic Tutorial, btw. I have a early 2011 MacBook Pro. My plan is to upgrade the HD to SSD. A Crucial M4 to be exact. If I use Disk Utility to clone the internal HD to SSD, will the SSD be divided into two partitions. To elaborate, I know the Mac comes with multiple partitions, one recovery and the daily use partition. Will the SSD be divided into two partitions, one for the exact image of the internal HD and one for what space is left? I have seen this happen on a Windows based PC where the cloning process was ruined because the cloning software literally cloned the contents down the exact size of the partitions. The left over space became a seperate partition of its own. It’s the only step holding me back and it doesn’t make sense to pay for third party software when the Mac comes with its own built in disk utility software. Please and thanks in advance.

    • Hi Cesar, The answer is, it depends on the OS and Disk Utility version. Before, I explain further, let me clarify that Disk Utility will only let you clone only one partition at a time and you cannot clone the entire drive as a whole in a single step. If you have multiple partitions, you will need to repeat the cloning exercise for each single partition. Also, by default Mac come with one visible partition, which includes both your OS and Data, and one hidden Recovery partition.

      Now, going back to my initial comment, when I initial used Disk Utility (while running OS X Lion) to clone my default OS partition, it used to include the Recovery partition along with it. But after I upgraded to OS X ML, I noticed that the cloning process didn’t include the Recovery partition.

      Also, you should be okay cloning from a smaller to a bigger capacity drive, cloning will not split the drive as you mentioned. Alternatively, you can also backup your OS and Data using Time Machine and then restore it to your new Drive. Again here the Recovery partition will be excluded. Note, I strongly recommended to backup your Data before doing the above. Hope this helps.

  12. Hi, I need some help. I used Disk Utility to clone my 2008 MacPro Tower’s main drive to a second internal drive because the main drive has been giving me boot problems lately (file folder with a question mark rather than the apple symbol). Everything copied to the new drive because when I hold down the Option key I can boot to it, I even then used Time Machine to restore from a previous day just to be sure EVERYTHING would be there. However, when I take out the main drive and put the new clone in drive bay #1, it won’t boot to the drive naturally unless I’m holding down Option. Is there any way to make the computer automatically boot this drive like it would the factory drive?

    • Hi Rob,

      Yes, you can change your default Boot Disk preference by going to “System Preferences > Startup Disk” and selecting the Disk you want to boot from by default.

  13. Mike Macchiaroli says:

    Vijay I am super glad I found this blog!! Very helpful. I am a PC guy but have been making the transition into the Mac/Linux relm. I followed your instructions and the process worked flawlessly. Thanks again and keep putting out material we need it!!!!

  14. Hi, Vijay

    I’m in panic mode. I’ve been experiencing kernel panics and I don’t have my system backed up. I’m an editor and all my media and project files are on an external RAID, a thunderbolt Promise, and I’m wondering if I can back up a copy of my system drive on my mbp late 2011 (750GB) to a folder on the promise without damaging anything else on that drive. Am I (mis)understanding that if I create a new disc image in disc utilities that I will erase precious data on the Promise? I don’t have anything free enough to handle the 700 GB of stuff from the mbp sys drive. I figured the thunderbolt fact would make the xfer speedier. Please help. All this and I’m supposed to deliver a project that I cannot call up.

    • Hi JO, The simplest and safest way would be to create a regular folder on your external RAID and copy over your data from MBP.

  15. Virginia says:

    This is the best explanation of how to create a clone that I’ve found. One question: once I create a clone of my MacBook Pro, can I use Time Machine with it to keep it up-to-date?

    • Hi Virginia, Unfortunately no, cloning is only a point in time copy of your partition. I would recommended using Time Machine to take a incremental / up-to-data backup.

  16. Hi Vijay, great article. I followed your tuturial but ran into problems. I´m trying to clone my hdd of 160 gb into a sed of 128 gb. I´m only using 84,13 gb on my original hdd but i´m told that the ssd is small. The new ssd is partitoned as should be. Any suggestions?

    • I mean ssd and formatted…
      I´m also copying right now using Super Duper, seems to bee working fine.
      Painstakingly slow…

      • Hi Tommie, That is strange, cloning using Disk Utility should work as long as the used space on the source partition is less than the target partition size. Can you copy me the exact error message. Also, are you cloning from Recovery Mode? (Assuming this is your primary / OS partition)

        • Hi Vijay, i did it from recovery mode just as you wrote, did’nt work though i tried it several times. I found a work around with Super duper witch worked just fine. I cloned my disk and test booted from it before i swapped disks i my Mac Mini late 2009. Then i swapped the disk and it works just fine exept for the fact that Sims III crashed for my kids. We will have to try it (the computer) out to see if it’s stable or if something’s wrong, it’s significantly faster anyway and i doubled the amount of ram from 2 gb to 4… I also downloaded trim enabler and it seems to be working. The error message is in Swedish so i don’t think it will help you:-)
          Thank’s for a great blog anyway, i’m learning loads of stuff…

          • Tommie Rönnblad says:

            Hi again Vijay. I have another problem now since i made the swap. I doubled the amount of ram as well from 2 gb 1066 mhz to 4 gb 1333 mhz, and mounted a ssd san disk ultra plus 128 gb. Now when i run sims 3 or call of duty they crasch or jams or the whole computer shuts down, other programs fails sometimes to but not every time. Got any idea as to why this happens?

            • Hi Tommie, Have you checked at what bus speed the new RAM operating, is it 1333 or 1066 mhz? In any case, I would suggest a “Process of Elimination” approach. First make sure the new hardware is properly seated and there are no loss connections. If that doesn’t help, then revert back to the old RAM and see if things run normally. Next, I suggest trying the same with the Hard Drive. If none of the earlier suggestions work, then I suggest copying the last few lines of “dmesg” logs to Apple Community Forum and ask for help. To do that, open “Terminal” and run “sudo dmesg” after the system hangs or crashes. I would ask you share the logs here, but I guess that won’t be of much use, it being in Swedish :)

              • Tommie rönnblad says:

                Hi again Vijay, i did as you suggested and swapped back to the old ram and now Call of Duty seems to be working fine again:-) I shall let my kids loose on Sims 3 and see how it goes…
                Thanks a lot…

  17. Chris Lu says:

    Hi Vijay,
    Thanks for all this helpful info.
    I bought and installed a new hard drive into my MacBook.
    (I wanted to expand my storage from 500G to 1T)
    Started the cloning process using CCC from an external hard drive.
    Everything was going perfectly – did everything just as you described above – but then my battery ran out! After I reconnected to power source, it keeps telling me hold power button down and then press again so that computer can restart. I have done this numerous times and just keeps taking me back to the same page.
    The cloning process obviously wasn’t complete so the new hard drive obviously isn’t working yet. I would guess that I need to re- format the new drive and start cloning all over again. But not sure how to do this? Any ideas? Or other suggestions?

    • Hi Chris, So have you already swapped your old drive with the new one? You can format your new drive using Disk Utility. Also, see my article on “Partitioning A Hard Drive On Mac Running OS X Lion” for additional help.

  18. Hi Vijay, Thanks for sharing your knowledge with us. I do prefer time machine as backups for my Mac. However, TM is often not bootable to get out a Mac out of crisis. I have used several utilities to clone my Mac. Now I also have a cloning app (Stellar Drive Clone) which I feel you would like to review.


    • Hi Vishal, I agree with you here. Also, thank you for pointing out another alternative cloning utility.

  19. Hi, nice straight forward, clear information here!
    A question, you say it completely clones like for like so say if i was to use my music program, with all my plugins, VSTs etc would i have to re- enter all the passwords, serials etc again or will it work identically including all applications?
    Also what would be the case if i was running snow leopard at the time but wanted to clone to a drive and install on operating system that has mountain lion, would certain applications not work because say they are 32bit but the new computer operates in 64bit?
    hope this made sense

    • Hi Richie,

      As far as the first part of your question is concerned, cloning will make an exact replica of your source partition. So say for example, you clone your OS partition which contains all the applications, then you could essentially replace your source with the target and boot of it. In short, no you should not have to reenter the passwords and serials for the same underlying hardware.

      Now, as far as the second part of the question is concerned, I do not think you can actually do that. Note, when you clone, the contents of the target partition is actually swiped and replaced with the contents of the source partition.

  20. Hi,

    Thank you for the procedure. I find it very useful. I tried cloning my 15″ MacbookPro Retina with 250GB SSD to a 1TB HDD external drive. I partitioned my 1TB HDD to Part1: 250GB (Clone PArtition) and 750GB(NTFS) for my personal files. I tried booting the cloned HDD to my 15″ Retina macbookpro and it worked. However, when I tried booting the cloned hdd to my new macbookAir, it did not work and my macbookair keeps turning off after choosing the boot option. Is there something wrong? Have anyone experienced this? The reason I am doing this is that I plan to bring my macbookAir anywhere ‘coz it’s too handy and when I want to use my profile (office profile) , I can just boot the cloned hdd.


    • Hi David,

      In most scenario’s the clone will only work on the same underlying hardware. The reason being, when you install the OS it is configured specific to the hardware it is installed on. Hence running the clone on a different piece of hardware usually fails, unless the difference in hardware is subtle.