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I'm about to replace my iMac's HD (250GB to 1TB). I'm planning to create an image of my disk right in m Time Capsule, and after the transition I need to clone the HD back.

Unfortunately Lion has no DVD, and I'm not sure if I should create one. Can I use my Snow Leopard disk to boot, and clone the Image to the new HD? Will the Time Capsule (which is connected via ethernet) be visible, and what about the difference between the image and the new HD in size? So, I'm not sure if it will work.

Another option would be to use the Time Machine backup to restore, but I'm not sure if I would trust it.

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up vote 1 down vote accepted

While the method you outline may work, Apple has much easier tools built into OS X that are meant for moving from one mac to a new one (which is essentially what you're doing). Basically you need to backup your data, create a Lion installation disk, install Lion on the new drive and use Migration Assistant to restore your data.


The Migration Assistant allows you to recovery your data from either a Time Machine backup or a bootable clone. You mentioned making an image on the Time Capsule. It's my understanding that you can use the Time Capsule for Time Machine or as an external hard drive, but not both. Even if you can get it to work, it's messy.

While you can recover from a Time Machine backup, I tend to be overly cautious when dealing with my data and like to have some redundancy. I would highly recommend buying a 250GB external drive (you can get them on Amazon for around $60) and making a bootable clone of your disk. It never hurts to have an extra drive around. Whichever way you decide to go, here's what you need to do -

  1. Run your normal Time Machine backup to make sure it's up to date.

  2. Create a bootable clone using Carbon Copy Cloner as previously recommended. If you go this route, CCC can also create a clone of the Recovery HD (explained below).

Create Lion Recovery Disk

When you installed Lion, it should have created a hidden partition known as the Recovery HD. You can boot from that just like you could from the Snow Leopard DVD. Apple has released a tool that will make a bootable copy of the Recovery HD on a USB thumb drive. If you used the Carbon Copy Cloner option above, you'll already have a copy of the Recovery HD on your external drive and can skip these steps (unless you want an install thumb drive "just in case").

  1. For some reason, some people don't have this partition installed. To verify it exists on your machine, shut down and then hold the option key while restarting. You should get a list of drives that you can boot from. Verify Recovery HD is listed. I'll cover what to do if it's not later.

  2. Download the Lion Recovery Disk Assistant.

  3. Insert a USB thumb drive. Apple says at least 1GB, but many are recommending at least 4GB.

  4. Run the tool and follow the instructions.

If for some reason you don't have the Recovery HD partition, you can still create the USB drive, it's just a bit more involved. TUAW has a good walk through of how to do this.

Replace Your Drive & Install Lion

You're ready! Pop in that new hard drive, then boot from the Recovery HD on the USB drive you just created or on the external drive you put your clone on (Hold down option key while starting the system and select the drive. It should be named Recovery HD). Install Lion just as you would install from DVD. You will need internet access since the installer calls home to get additional files. The process took about an hour for me.

Copy Data Using Migration Assistant

Once the installer is done it will reboot your mac from the new drive and you'll see the Lion welcome screen that greets purchasers of a new mac. Follow the prompts and you'll be given the option to move your accounts from an old computer or drive. You'll be asked if you want to recover from a Time Machine backup, another mac or an external drive. If you have the clone, choose the external drive option, if not select Time Machine. You'll then be presented with options on what data you want to migrate. Just select everything and let the Migration Assistant go to work.

When the tool is finished you can reboot your mac and everything will be back to where it was. You won't even notice you've got a new drive until you want to use all that extra space.

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Thanks a lot for the deep explanation. About using TC for Time Machine backups and external hard drive, yeah it works fine, and I don't find it messy at all. Anyways, the idea behind the disk image was to avoid reinstalling the system, I'd like to simply say "clone it back" and avoid the detailed install part. However I think you convinced me to use the Time Machine backup to restore things. Unfortunately HDs are not that cheap here (I'm outside the US) so I'll probably keep my data in one place only during the transition. – winck Apr 27 '12 at 19:47
I created a install USB drive (I had the Lion install image here), it should speed things up a little since this drive with the full image is far more complete than the 1GB created by Apple's recovery tool (won't depend on the internet too much). Thanks for your help. – winck Apr 27 '12 at 19:52

You can do this with Time Machine, but there is another method, if you have the equipment. Instead of Time Machine, use a shareware disk cloning utility. I use Carbon Copy Cloner.

If you are paying someone to swap out the hard drive in your iMac, ask them if they can do the following for you.

Don't erase your main hard drive just yet. Take the new hard drive that you are going to install in the iMac and put it in an external enclosure that uses USB or FireWire, and connect it directly to the iMac. Use Disk Utility to make sure it is properly formatted to make it a bootable Mac OS X volume. Install Carbon Copy Cloner on Mac OS X on your main hard drive and us it to completely clone that drive to the external drive. Check the Carbon Copy Cloner settings to make sure that it will create a bootable duplicate drive.

Then you can remove the new drive from its enclosure and install the new drive into the iMac and boot it up.

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+1. Succinct and direct. As the "external enclosure" I recommend Voyager: <>;. It's a dock for bare drives, handles various sizes and has multiple I/O connections. AND to be clear, "clone" means "bootable". – radarbob Apr 26 '12 at 17:03
That's what I had in mind initially, I think it's the easiest way. The problem is that I can't find any similar docks, cables, or cases here in my city, and I'm not sure if it would be worth traveling to buy any of these. Also, it's not as cheap as it is in the US, and I don't plan doing this again — it would be used only once probably. Yes, I, myself, am going to do the replacement :-) what an adventure. I bought a new Time Capsule, and I'm going to take the old Time Capsule HD off, and put it in my iMac. – winck Apr 27 '12 at 19:56
Please be sure you have the proper tools to open your iMac and handle the glass screen! Opening and reclosing an iMac without damaging it is difficult. – user9290 Apr 27 '12 at 20:27
Here is one toolkit you should consider purchasing. – user9290 Apr 27 '12 at 20:28

You might also want to check out AppFresh, which connects to your iUseThis account and automatically downloads everything you've flagged as 'I use this.' In some cases it can also install the software, plug-in, etc for you.

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