Previous 1 2 Next 18 Replies Latest reply: May 28, 2011 5:51 AM by Reuben Feffer
Reuben Feffer Level 2 Level 2 (205 points)

I have two identical 21.5-inch iMacs. I want to move everything from iMac A to iMac B, restoring iMac B from iMac A's Time Machine backup drive.


I've done this before, so I know approximately what I'm doing. But, my question is, when I boot iMac B from a DVD to begin the process, should I use the iMac Install Disk that iMac B came with, or should I use my retail version (white box) of Snow Leopard?


The Mac OS X Install Disc that iMac B came with says it's version 10.6.4.


My retail version of Snow Leopard says it's version 10.6.0.

iMac, Mac OS X (10.6.7), 21.5-inch, Mid 2010, 3.2GHz
  • noondaywitch Level 6 Level 6 (8,130 points)

    Then the retail disc won't load anyway. You can't boot from an OS version earlier than the one it shipped with.


    As for transferring everything, it's far simpler to link the iMacs by firewire and use Setup Assistant when prompted by the installer. That way you avoid possible multiple accounts and permissions issues.

  • Barry Hemphill Level 8 Level 8 (36,755 points)

    Hello Reuben:


    If you do have a FireWire cable, you may use migration assistant and point it at your Time Machine backup.



  • Reuben Feffer Level 2 Level 2 (205 points)

    From what I understand, Migration Assistant doesn't provide an identical copy of one Mac to the other, but Restore System from Backup does. Is that right?


    If the internal hard drive of iMac B was completely reformatted and erased, how would the computer not be able to boot from my retail version of Snow Leopard (10.6.0)? Surely it would work just fine.

  • macjack Level 9 Level 9 (50,625 points)

    Hi Reuben,


    Several things to keep in mind...


    First, without the OEM install disk you iMac shipped with, you will not get the bundled software.


    Second, I believe noondaywitch meant that the OEM disks are for the computer they shipped with only, as they are hardware specific. However, if your Macs are identical and you're installing a newer version it should work.Still, it's possible you may get a message "this disk is not for this computer".


    Your best option is as Barry says, while in Setup Assistant after the clean install migrate from TM backup.


    Good luck.

  • noondaywitch Level 6 Level 6 (8,130 points)

    Your Mac shipped with 10.6.4; it won't boot from 10.6.0. Try it by all means, but it's rather pointless anyway as the retail doesn't have iLife and the other bundled software.


    Reuben; OP says the disc that came with iMac B (to use his reference) is 10.6.4. He's not trying to use the wrong disc in that regard.

  • Reuben Feffer Level 2 Level 2 (205 points)

    Right, so I should use the Mac OS X Install Disc (10.6.4) that iMac B came with, to reinstall Snow Leopard on iMac B.


    And then, during Setup Assistant, I will use the Restore System from Backup option to make a perfect clone of iMac A on to iMac B. Both iMacs are identical in terms of hardware. Exactly the same model number, hard drive size, memory, screen size, etc.


    Also, yes, the retail version of Snow Leopard doesn't include "iLife and the other bundled software". I understand that. But both iMacs (A and B) only came with Snow Leopard and iLife, they didn't come with any other bundled software. And I own retail versions of Snow Leopard and iLife '11, so I'm covered.

  • Reuben Feffer Level 2 Level 2 (205 points)

    One more question, when you say the hardware between the two machines has to be IDENTICAL, how identical are we talking?


    Both of two iMacs I have here are 21.5-inch, Mid 2010. They're both the second option out of the four iMacs that were available at that time, and they've both got the same family name: A1311.


    However, looking through About This Mac > More Info, some of the internal components are very slightly different. For example, iMac A has a HL-DT-ST DVDRW drive, whereas iMac B has a OPTIARC DVD RW AD-5680H.


    Will these slight differences cause an issue if I restore iMac B from iMac A's time machine backup?

  • C. D. Tavares Level 1 Level 1 (120 points)

    Seriously, the fastest and most straightforward way to do this is to connect the two machines with a FireWire cable, boot the second one in FireWire Transfer mode, and use either Disk Utility, Super Duper, or a similar utility to simply copy the first drive directly onto the other.  Saves all the slowness of booting off opticals.


    The failure modes to watch out for here are that the machine's networking names will be identical and serial-numbered and copy-protected software (like Adobe's) will start complaining.  But you'll have those two issues if you do it from a backup anyway.

  • Barry Hemphill Level 8 Level 8 (36,755 points)

    Hello Reuben:


    A final note after reading the thread again:


    Discussing what might work is confusing and counter-productive.  As I said (and Macjack reinforced) the way that will work is to use the migration assistant (hook your external drive to the new Mac) and point migration assistant at your most recent Time Machine backup.  Copying is a bad idea….might work, but might not.  Reinstalling OS X on the new machine is (IMHO) a waste of time, but I do understand that you have your own reasons for wishing that to happen.



  • C. D. Tavares Level 1 Level 1 (120 points)

    Seems unnecessarily dismissive.  I've used the copy procedure on literally scores of Macintoshes and Macintosh replacement drives over the past 20 years, and it has never once failed.  It's the simplest, most efficient, and effective technique to get this particular job done, which is important to me as an Apple-Certified technician who does this for a living.

  • Reuben Feffer Level 2 Level 2 (205 points)

    How is this "copy procedure" better than restoring iMac B's hard drive from iMac A's Time Machine backup? I really like the idea of using this restore system from backup method, because I've done it before. What's the catch with it?

  • C. D. Tavares Level 1 Level 1 (120 points)

    No "catch," really.  The Transfer Mode is just much faster (no DVD booting) and more direct (equipment needed: one cable) than the backup process.


    The backup capability is invaluable if your source machine has gotten broken, or stolen, or whatever… but as long as it works and you have it, you may as well take advantage of the fast and direct route.

  • ds store Level 7 Level 7 (30,315 points)

    Reuben Feffer wrote:


    How is this "copy procedure" better than restoring iMac B's hard drive from iMac A's Time Machine backup? I really like the idea of using this restore system from backup method, because I've done it before. What's the catch with it?


    It's called "cloning" and since you have two identical machines the hardware drivers on A will work on B.


    The only thing you might not be able to do is of course clone more data to a smaller capacity drive, so as long as the drives are equal in size, or drive B is greater than drive A (great for upgrading boot drives to larger capacities) you can clone. (make/model doesn't matter)


    Time Machine is a image backup method only, it's not bootable and you can't have access, it's for newbies who constantly delete their files by accident, it's better than nothing for them.


    Cloning puts the whole OS X boot drive/partition onto another drive and "blesses" it so OS X can boot from it, simply hold option while booting a Mac and you'll get a choice of drives to boot from. You can take a external drive clone to another similar Mac and option boot off of it as well, which should come in handy in your case.


    Cloning is easy as pointing A at B and click "clone" and it can auto-update as well on a time schedule of your chosing, if your boot drive fails to boot one morning (they do that) just hold option and boot from the clone and your back in business. TimeMachine can't do that. (I wished it did)



    What C.D. Taveras is describing is booting the target Mac in Firewire Target Disk Mode, which makes B look like any other hard drive to A, thus using cloning software like the free Carbon Copy Cloner on A to facilitate the clone directly to the other machines hard drive. Since the two machines are identical in make and model, you can do this.


    You need preferably a Firewire 800 to 800 cable for the fastest transfer, but a Firewire 800/400 adapter cable (drops to 400 speeds) or 400/400 works as well, just slower than 800.


    If you buy a exteral Firewire 800/400/USB drive, a Firewire 800 cable should be included.


    So you can use that cable for the Firewire Target Disk Mode clone from A to B.


    Then use the external hard drive as a emergency bootable clone for the two machines although user data on one of the machines will need it's own backup method, likely TimeMachine or another clone.





    By the way, if you got a Bootcamp partition you can use Winclone in OS X to image it to another drive.

  • Reuben Feffer Level 2 Level 2 (205 points)

    Can you do this Firewire Target Disk Mode procedure using all Apple software? I mean, can I use Disk Utility on the host computer (iMac A) rather than Carbon Copy Cloner? If the answer is yes, can someone provide me with very clear simple instructions? What exactly do I have to do in Disk Utility?

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