Feb 112010

I decided recently to upgrade the storage in my Mac Pro. Currently it had 3 hard drives in it

  • 320 GB – the one that came with the computer. This is little changed from when I got the computer as I immediately added a 500 GB and 750 GB to the machine as soon as I got it
  • 750 GB – this is my startup volume, and has all the applications and documents on it. 90 GB free. It contained 1,803,033 files using 608.5 GB (653,331,116,032 Bytes).
  • 1000 GB – this is my Time Machine volume, and has Time Machine backups going back 16 months to October 2008. 135 GB free. It contained 16,765,985 files using 787.6 GB (845,667,311,616 Bytes).

So for the upgrade – the plan was to add a 2 TB drive into the last empty drive bay in the Mac Pro to become the Time Machine volume, then clone the 750 GB drive to the 1000 GB drive, then use the 750 GB drive as a network backup volume perhaps.

So the first step was to attempt to move the Time Machine volume. This article http://www.macworld.com/article/146085/2010/02/migratebackups.html indicated it should be a fairly straight forward task. So I followed the instructions and set out. It took about 2 hours to copy all the data from the 750 GB drive to the new 2 TB drive, then I waited another 2 hours for the “Verifying” phase to complete, and just as it appeared success was at hand, a dreaded error message.

[code lang=”xml”]2/10/10 5:51:41 PM Disk Utility[10086] Could not restore – Operation timed out[/code]

Well that wasn’t very helpful. Thinking that it was finished verifying I just accepted that thinking all would be good, but attempting to check the disk with Disk Utility gives
[code lang=”xml”]2/10/10 5:52:36 PM Disk Utility[10086] Verifying volume “2 TB”
2/10/10 5:52:36 PM Disk Utility[10086] Starting verification tool:
2/10/10 5:52:36 PM Disk Utility[10086] Checking Journaled HFS Plus volume.
2/10/10 5:52:36 PM Disk Utility[10086] Invalid node structure.
2/10/10 5:52:36 PM Disk Utility[10086] Volume check failed.
2/10/10 5:52:36 PM Disk Utility[10086] Error: Filesystem verify or repair failed.
2/10/10 5:52:36 PM Disk Utility[10086]
2/10/10 5:52:36 PM Disk Utility[10086] Disk Utility stopped verifying “2 TB” because the following error was encountered:
Filesystem verify or repair failed. [/code]

Even less impressed now. So I decided to run a Disk Repair on the 750 GB Time Machine volume – that took over 6 hours and found a few errors which it said were fixed. Then I tried the MacWorld procedure again, with at the end of another 4 plus hours the same frustrating result – an error message and a failure to be able to verify the drive.

Googling the error message led to a number of other sites with people complaining of similar problems. I tried the several suggested solutions, including initially making a partition on the new drive that was only a little larger than on the old drive, doing the Copy, and then enlarging the partition. This time the copy was successful, but enlarging the Partition wasn’t.

By now 3 days have passed me by.

So I tried Carbon Copy Cloner by Bombich Software, but when that was unable to manage the task I found that copying Time Machine volumes isn’t supported by Carbon Copy Cloner.

So I then tried SuperDuper! by Shirt Pocket Software. This set out to do the copying, but seemed agonisingly slow. After some 8 hours it had copied less than 6,000,000 of the files, so having read more sites that indicated that the MacWorld process, or very similar variations thereof really would work, I aborted the SuperDuper process and started another process using Disk Utility, but alas this too failed.

So it was going to have to be SuperDuper!. I set that running yesterday, and it finally completed today after an elapsed time of 17 hours 22 minutes.

[code lang=”xml”]| 04:16:25 PM | Info |       Cloned  777.51 GiB of data in 62536 seconds at an effective transfer rate of 12.73 MiB/s[/code]

According to Activity Monitor, at times the copy speed was above 100 MB/sec – presumably when copying large files, but for much of the time the copy speed was around 3-4 MB/sec as it copied the tens of thousands of symlinks that make a Time Machine volume work.

I don’t know what happened to the apparently missing 1,741,753 files (16,765,985 – 15,024,232), but once the copy was finished, Disk Utility reported that the drive had 16,269,744 files on it – a difference of a mere 496,241!!

When it was all done, and a “Repair Disk” from Disk Utility showed that all was normal, I opened the Time Machine preferences, selected the new 2 TB disk as the Time Machine Disk, and nervously waited for it to complete the first backup. This took a bit over 2 hours for Time Machine to scan the volume, Spotlight to get it indexed for Time Machine, and then the first backup done in several days to run, but HAPPILY when it was finished it recognised that the oldest backup was October 22, 2008, and reported that the next backup would be in about 45 minutes time. That backup ran successfully and completed in only a few minutes – it seems we’re back to normal, with a whole TerryByte of free space on the Time Machine volume now!!

So the next challenge is cloning the 750 GB drive to the 1 TB drive. Tomorrow is another day!!

  2 Responses to “Copying a Time Machine Volume”



    your statement that “copying Time Machine volumes isn’t supported by Carbon Copy Cloner” is incorrect.

    CCC will not copy a Time Machine volume when performing a **file-level** copy. However, when performing a **block-level** clone, CCC is able to clone a Time Machine volume.

    from the CCC knowledge base (http://help.bombich.com/faqs/troubleshooting/cloning-time-machine-backup):

    “For this reason and others, support for directory hard links has not been implemented in CCC’s file-level synchronization engine. CCC’s block-level cloning engine, on the other hand, does preserve directory hard links, and is therefore capable of cloning a Time Machine volume.”


      Thanks for this update – the article you reference is dated 29 June 2010 – 4 months after I’d spent several days trying to achieve this without success.

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