Using Disk Utility to Clone/Duplicate entire hard drive.

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29 points

Using Disk Utility to Clone/Duplicate entire hard drive.

I have read many post that touch on this question but none have cleared up my questions, and many have just lead to more questions on my part.

I want to use the included Disk Utility program to copy my entire hard drive to another.

Because I only plan on backing up the entire drive once or twice a year, I do not feel I need Carbon Copy Cloner or Super Duper. Also I would like to understand how to accomplish this with the application I already have.

Having read all the help pages and posts I can find, I understand the general concept of using the "Restore" function in DU, but have these questions still:

1. My current HD is a 250GB partitioned with one volume "Macintosh HD" I am going to install another 250GB hard drive into bay 2. Do I need to partition this drive first?

2. Do I need to format this drive?

3. Do I need to erase this drive?

4. Do I need to use the security feature to "Zero" this drive?

5. It seems to me that if I am doing a bit for bit clone the partitioning and format from the source drive would just come over in the copy...no?

6. As the source for the "Restore" do I want to select the parent 250GB disk drive, or should I select the "Macintosh HD" volume?

7. As the destination for the "Restore" (if I had to partition and format) do I want the new 250GB drive or the "Backup" volume?

8. If I have to partition and format the new drive first, I understand that I want the GUID partition table and the MAC OS Extended (journaled), can someone explain what the heck that means?

Mac Pro 2.66, Mac OS X (10.5.2)

Posted on Feb 23, 2008 11:11 AM

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Answer 1

Kappy

Level 10

362,007 points

Feb 23, 2008 12:28 PM in response to toddlydavis

How to Clone Using Restore Option of Disk Utility

1. Open Disk Utility from the Utilities folder.
2. Select the backup or destination volume from the left side list.
3. Click on the Erase tab in the DU main window. Set the format type to Mac OS Extended (journaled, if available) and click on the Erase button. This step can be skipped if the destination has already been freshly erased.
4. Click on the Restore tab in the DU main window.
5. Select the backup or destination volume from the left side list and drag it to the Destination entry field.
6. Select the startup or source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.

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Answer 2

toddlydavis Author

Level 1

29 points

Feb 23, 2008 2:58 PM in response to Kappy

Kappy, I have read your other posts with interest. I believe that your reply answers number 6 and 7 but that still leaves me with the other questions. It seems to me that if I have to pick the volume for the destination, I would have already had to create that volume on the empty blank new disk through partitioning and formating, right?

Thanks for your fast response.

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Answer 3

Kappy

Level 10

362,007 points

Feb 23, 2008 3:03 PM in response to toddlydavis

I apologize for missing that part of the intro.

For a new drive here's the modified procedure I suggest:

Extended Hard Drive Preparation

1. Open Disk Utility in your Utilities folder. If you need to reformat your startup volume, then you must boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger or Leopard.)

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.

3. Click on the Options button, set the partition scheme to GUID (only required for Intel Macs) then click on the OK button. Set the number of partitions from the dropdown menu (use 1 partition unless you wish to make more.) Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the volume(s) mount on the Desktop.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process will take 30 minutes to an hour or more depending upon the drive size.

Steps 4-6 are optional but should be used on a drive that has never been formatted before, if the format type is not Mac OS Extended, if the partition scheme has been changed, or if a different operating system (not OS X) has been installed on the drive.

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Answer 4

toddlydavis Author

Level 1

29 points

Feb 23, 2008 3:50 PM in response to Kappy

Why would I want to reformat my startup volume in this operation?

So we are cloning a volume not a drive, right? If in theory I had multiple partitions/volumes on the source drive, this operation would not copy all of them to the new disk, right?

I thought that a clone of a drive was just that, a complete exact copy, but I guess that is not technically what we are doing here.

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Answer 5

Kappy

Level 10

362,007 points

Feb 23, 2008 7:49 PM in response to toddlydavis

You are not reformatting your startup volume. You are formatting the new drive. You are not cloning. The described procedure is what you do to prepare a new drive for use that has not been prepped for use on a Mac. If you have multiple partitions on the old drive, then you can create multiple partitions on the new drive during the partition step outlined in the procedure. After you prep the new drive, then you can clone your old drive to it:

How to Clone Using Restore Option of Disk Utility

1. Open Disk Utility from the Utilities folder.
2. Select the backup or destination volume from the left side list.
3. Click on the Erase tab in the DU main window. Set the format type to Mac OS Extended (journaled, if available) and click on the Erase button. This step can be skipped if the destination has already been freshly erased.
4. Click on the Restore tab in the DU main window.
5. Select the backup or destination volume from the left side list and drag it to the Destination entry field.
6. Select the startup or source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.

Repeat the process for each partition (volume) you want to clone.

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Answer 6

toddlydavis Author

Level 1

29 points

Feb 23, 2008 8:09 PM in response to Kappy

The question about reformatting the startup volume came from your step 1: "If you need to reformat your startup volume, then you must boot from your OS X Installer Disc."

I did not think that is what I wanted to do.

I am correct that partition and volume are almost interchangeable terms here? You can only have one volume in a partition, right?

So the use of the term Clone here really should be "Copy of the Data" as I understand it. The new volume (to be backed up to- the destination) can be named anything. If we were truly cloning a drive the volumes and partitions would exactly match the source including the names of the volumes. I am curious if the programs people keep referencing (Carbon Copy Cloner and Super Duper) are copying volumes as well or if they are cloning a drive in its entirety. I assume that when law enforcement get hold of a drive that may have evidence, they truly clone the entire drive, not just copy partitions. If you truly clone a drive bit for bit would not the format and partitioning transfer over as well?

I do not mean to beat this into the ground, I really am just trying to fully understand the concepts here. Once I grasp this, I will not need to remember the specific steps, as the foundation will make sense to me.

Thanks for your time.

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Answer 7

Kappy

Level 10

362,007 points

Feb 23, 2008 8:25 PM in response to toddlydavis

Correct, you don't want to reformat your startup volume, therefore you can work with the new drive running DU from your system volume.

Correct, partition and volume mean the same thing.

Almost correct. A clone is not a special type of copy of the data. One that includes all invisible system files needed as well as blessing the system so it will be bootable. You cannot clone a system by simply copying files using Drag and Drop.

Correct, you can name the destination volume anything you want including the same name as the source. The operating system has no difficulty distinguishing between to volumes with the same name, although you might have a problem keeping them straight on your Desktop!

There are different ways of creating clones. Most backup programs use a basic form of file copy. As far as I know only Carbon Copy Cloner is capable of making block-level copies (similar to a bit copier except that CCC copies an entire block - 512 bits - at a time. For this to work CCC requires that the source and destination volumes be at least equal in size otherwise it defaults to a normal file copy method. The police would probably use true bit copiers because it circumvents most copy protection schemes.

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Answer 8

toddlydavis Author

Level 1

29 points

Feb 24, 2008 7:35 AM in response to Kappy

After using the erase with zero option in the prep of the hard drive, do I still need to erase all that zero data before or during the duplicating process where I have selected the from and to volumes?

Also, I am really curious, if you had a completely blank new hard drive, and you were able to preform a bit for bit clone of another drive, would the new drive need to be formated and partitioned first, or would that data come over from the orginal drive?

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Answer 9

Kappy

Level 10

362,007 points

Feb 24, 2008 10:03 AM in response to toddlydavis

Once you do the zero data erase you don't need to re-erase the drive. However, if you were to use CCC to do a block-level clone you must also select the option to erase the Destination first. Although it isn't a requirement for a drive already erased, CCC has that requirement or it will not do the block-level clone.

A true bit-level copy would not require prepping the drive if the bit-copier copied everything including the disk's "data block" which holds all the structural information on the drive's layout and directory. Generally there is only one reason one needs to use a bit copier (other than for forensic needs) and that is piracy.

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Answer 10

Feb 26, 2008 7:59 AM in response to Kappy

If I understand correctly what you meant by bit-level copying, then I have a legitimate reason (not piracy) to use this for backing up. (In fact, in searching for a way to do this I came across this thread.)

I have a single external drive that I have cloned three of my Macs to using SuperDuper!. I now want to duplicate this entire drive (a bootable clone for each of my three macs and 1 storage space for 4 total partitions) to a second external drive to store offsite. Unfortunately, neither CCC or SD! will clone an entire drive with multiple partitions. This means I have to clone each partition individually.

A way to clone them all at once (applescript, or automator script perhaps) would be a great time saver. Any ideas? Thanks.

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Answer 11

Kappy

Level 10

362,007 points

Feb 26, 2008 8:28 AM in response to lepidoptera

Sorry, but there is no software available for the Mac that does bit-level copying that I'm aware of. You will have to do individual volume clones.

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Answer 12

Feb 26, 2008 8:46 AM in response to Kappy

Yup, that confirms what my research has found. Oh, well here we go with 4 clones in a row! It's time consuming, but at least its painless. Thanks for your help.

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Answer 13

toddlydavis Author

Level 1

29 points

Feb 29, 2008 9:51 AM in response to Kappy

Thank you for your help, Kappy. I followed your steps exactly and it worked perfectly. In fact I am running off the Clone now. (Clone is capitalized as that is what I named my new volume, creative huh?)

Question: When I was done with the restore in DU, the clone was smaller than the Macintosh HD. The Macintosh HD was about 20.2GB and the clone ended up at about 18.3GB or so. Why the discrepancy? I would think that if it was an exact copy, it should be exactly the same size. There does not seem to be any issue, as I can find no issues with my clone, save for 1 program needing to have its save to path adjusted because it burrows down all the way from the Macintosh HD path and needed to have the parent changed to Clone.

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Answer 14

toddlydavis Author

Level 1

29 points

Feb 29, 2008 9:56 AM in response to toddlydavis

?

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Answer 15

Kappy

Level 10

362,007 points

Feb 29, 2008 1:13 PM in response to toddlydavis

Restore does not copy everything. There are certain files that do not require copying such as cache files. These files are not included. Also, cloning has the beneficial effect of defragmenting the drive which probably saves a little more space.

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