A Bigger Time Machine without Changing History

I had a 160GB drive holding my Time Machine backups. Because I wanted to backup external disks, and still wanted to be able to travel about a year back in time, I bought a 1TB USB disk. Stephen Foskett wrote a great article about how he migrated his TimeMachine backup to a larger disk, but it’s lengthy and misses one essential step.

I decided to give you the short version, this blog post describes how I migrated Time Machine to the new disk without losing any data in 11 easy steps.

  1. Get a new, big, empty drive with a single Mac Journaled partition on it. Give it a good name so you can keep it apart from the original Time Machine drive.
  2. Open the Time Machine configuration screen, and turn off Time Machine.
  3. Unmount and remount the Time Machine drive, it should show up as an ordinary orange drive on your desktop.
  4. Open Disk Utility, and click the “Restore” Tab.
  5. Drag the “TimeMachine” partition which is on the old drive to the “Source” box.
  6. Drag the large partition on the new drive to the “Target” box.
  7. Select “Erase Target”. If you do not check this, the disc copy will fail. This is the essential step I mentioned earlier.
  8. Click “Restore”, double check the popup warning to see if you are doing the right thing and press “Restore” again. After a number of hours, depending on the speed of your USB hub and the size of the disks, you will see 2 identical drives on your desktop. The new drive should have a lot more space available. In my case, it took 5 hours to migrate 160GB to the new drive.
  9. Unmount the old Time Machine drive, physically disconnect it to be sure.
  10. Open the Time Machine configuration screen, and turn on Time Machine.
  11. In the Time Machine configuration screen, press “Change drive” and select the new drive. You will see the disk icon turn into the green TimeMachine drive icon. You’re done.

You can test Time Machine now by clicking the Time Machine icon in your dock and see that you still have all your history. Once you’ve verified that all your history is still there, you can use your old Time Machine drive for something else (reformat it).

You might also want to check your spotlight settings to not include your Time Machine drive for searching. Because I did not touch the volume name on the new drive, I didn’t have to change any settings, but I checked to be sure.

Bonus tip:
Now that you’ve got a large backup drive, maybe it’s time to think about backing up your external drives. Make sure all the drives you want to backup are connected, and open the Time Machine configuration screen. Click on “Options…” and remove the drives you want to back up from that list.

42 Responses to “A Bigger Time Machine without Changing History”

  1. How To Move OS X Time Machine Backups To A New Disk | Stephen Foskett, Pack Rat Says:

    [...] Update: See Rolfje’s blog for streamlined Time Machine migration steps. [...]

  2. basti Says:

    Hey thanks buddy! I tried it many times without the essential 7th step and then I found your post here… You saved my day :-)

  3. rolfje Says:

    Glad to hear. Enjoy! :-)

  4. Geoff Liang Says:

    thank you. merci beaucoup.

  5. For the Record « java jive Says:

    [...] in Geek How to migrate Time Machine Hard Disks the right [...]

  6. Rich Says:

    Many thanks for this simple guide – made it very easy to migrate to a larger disk after I outgrew my old one.
    [RICHR]

  7. RIchard Says:

    Thanks for this – my new Black Friday drive is now happily waiting to be filled with back-ups galore!

  8. Transferring current Time Machine backups to another external HDD? - MacTalk Forums Says:

    [...] is actually a better version of the same thing (the tip above missed one critical step) A Bigger Time Machine without Changing History Rolfje’s blog __________________ 24" Alu iMac 2.4 w/ 4GB [...]

  9. Beau Giles Says:

    Losing, not loosing. :P

  10. rolfje Says:

    You’re right. Fixed. Thanks!

    http://www.thefreedictionary.com/losing
    http://www.thefreedictionary.com/loosing

    :-)

  11. Hildis privates Weblog » Time Machine Backup mit neuem Mac weiter benutzen Says:

    [...] das Umkopieren von der alten 500MB Festplatte auf die 1GB Platte mittels “Wiederherstellen” im [...]

  12. Tyler Says:

    did the suggested method and keep getting same error. says “disk restore failed. timed out” please help me.

  13. rolfje Says:

    I’m not 100% sure, but “Time Out” seems like a different problem. Maybe you should try to just format the 1TB drive and see how that goes. If that also reasults in a timeout, you may have a faulty drive.

    You can also try to format the drive on a different machine, at a friends house.

    If that doesn’t work, and you’re sure that the drive is working correctly, you can try reading the Apple support forums, or calling the Apple support desk.

  14. bigbigbarra Says:

    you’re the man, rolfje. cheers 8)

  15. Worby Says:

    Thx for a great How-To :)

    May be worth adding that the new volume is verified as part of the restore process.

    Moving from a 500GB disk to a 1GB disk took 17 hours for me.

  16. Espen Says:

    First, thanks for a great howto!

    Now for some problems: I tried this yesterday, moving from a 750GB MyBook to a 1TB MyBook, but got the “Timeout” error just as Tyler reported. The copy seems to have been complete, but the copy has B-tree errors and is not repairable.

    My hunch is that this is due to the sleep mode of the MyBook disks, which has bothered me before. Does anyone know of an easy trick to force both the two disks to NOT fall asleep during the copy?

  17. Espen Says:

    SOLVED!

    I tried it once more with a different MacBook Pro, this time with both disks connected directly to the mac (one on FW800, one on FW400), but with no luck.

    Then I got an idea: I reduced the volume size on the new disk to about the same as the old disk (a few bytes more), and tried with the first mac again (both disks on FW800) – and it worked! Immediately after the successful copy, I extended the partition again to fill the whole 1TB disk. I now use the larger disk for Time Machine, and it seems to work perfectly.

    (Please note that the repartitioning took a long time! I think 45 minutes)

  18. Arjan Says:

    Hmmm, I came across an extended attribute that holds the ID of the backup disk. As in the above instructions this ID is not changed, I assume that Time Machine currently does not validate that value (or, maybe worse: that during the copying above the disk id is copied as well — if so, then fully erasing the original disk might prevent future issues?)

    See com.apple.backupd.SnapshotVolumeUUID (“the UUID of the volume in question, matching the one you get with diskutil info /Volumes/Volume-Name”) at http://earthlingsoft.net/ssp/blog/2008/03/x5_time_machine

  19. Rich Says:

    Thanks very much for this great tip. I wanted to switch out a 1TB hard drive connected to my 24″ iMac Aluminum and followed the instructions and it worked exactly as you said…a perfect copy. I had about 500GB of data on my Time Machine. Both the new and original drives were connected via USB and it took about 12 hours for Disk Utility to copy and verify everything. I left it running overnight and the next morning I had an exact copy ready to go. Thanks again…great stuff!

  20. Tormentum Says:

    Just an FYI for those wanting to do this in the other direction (Larger -> Smaller disk) for whatever reason (re-utilization of disks etc), this works fine so long as the currently used disk space on the current larger drive is less than the total disk space on the smaller drive.

  21. Thomas Says:

    Moved 350 GB from USB drive to new 1 TB FW drive. Took ~4 h. Worked exactly as described. Easy!

  22. Juicylish Says:

    Went from 160GB to 1TB today. Entirely straightforward, thanks to you. Took a couple of hours (old drive connected USB2, new drive firewired). Great stuff.

  23. Arjan van Bentem Says:

    For those who are using sparse bundles (like on a network backup) and want “A Bigger Time Machine WITHOUT CHANGING DISKS”, read on! :-)

    In a sparse bundle, any unused space is not reclaimed until really needed. If you ever removed some huge files from your backups, or if expired (hourly, daily) backups may have contained huge files, then compacting the sparse bundle makes the free space available right away. When not doing that, Time Machine will in fact compact when really needed, but FIRST might try some pre-backup thinning by removing (a few?) old non-expired backups.

    In my case, I freed about 200GB on a 300GB disk, after I discovered a runaway MySQL log that partly already was removed from expired hourly backups, and partly I removed myself. (This, by the way, proves how excellent Time Machine works in the background, as I discovered this quite late!)

    See http://serverfault.com/questions/9422/what-is-time-machine-doing/39310#39310 for some details, with thanks to Adam Cohen-Rose’s tests at http://adamcohenrose.blogspot.com/2008/04/time-machine-update-fixes-sparse-bundle.html

  24. MelanieIs Says:

    Thanks so much! I bought a 1T drive and transferred the time machine backups easily – but then hated the drive and transferred everything back again. Once I get another one, I’ll got for three…

  25. Zane Selvans Says:

    Hmm. Now how do we upgrade from one computer to another without losing the backup history?

  26. rolfje Says:

    Moving the TimeMachine to a new mac (or in this case, the same Mac with new internals, which is essentially the same): http://www.macosxhints.com/article.php?story=20080128003716101

    The MAC address is the key to your TimeMachine root. ;-)

  27. Arjan van Bentem Says:

    Unless you’re only backing up your documents and email, I disagree. To allow for a full restore, changing the MAC address on the backup disk would only be safe if that very same backup was first used to do a full restore on the new, upgraded Mac. Not all Macs are the same. The macosxhints.com article described repairs of the hardware, using the very same internal hard disk afterwards.

    Maybe one could make the contents of the old backup match the new Mac by forcing a deep traversal (for this to happen, fseventsd on your Mac must be fooled into “events log in /Volumes/.. out of sync with volume. destroying old logs.”, followed by Time Machine’s “Event store UUIDs don’t match [..] Node requires deep traversal”). And then maybe this new backup, or any newer backup, can be used for a full system restore (but not using backups that were created before the deep traversal, as I think those certainly do not match your current Mac).

    I feel that’s not worth the risk. Just keep your old backup and create a new one. If, at any time, you want to restore files from any Time Machine Backup, then simply hold down Option while launching Time Machine (or while clicking the icon). This will change “Enter Time Machine” into “Browse Other Time Machine Disks”.

  28. Links for the week of August 20th, 2009 | Amateur Earthling Says:

    [...] A Bigger Time Machine without Changing History – A method of switching to a larger Time Machine backup disk without losing your existing backup history, and without having to resort to any .plist editing or command line magic. Seriously Apple, why isn't this just built in? [...]

  29. Mike Says:

    Thanks for this. I was able to upgrade my Time Machine disk from 1 TB to 1.5 TB using these instructions. Both were external disks attached to an Intel Mac mini.

    I did, however run into a few problems before getting it right. After 15 hours of copying and verifying, I encountered the “timed out” error reported by Tyler and Espen. Espen’s solution of making the partition on the new disk just slightly larger than the old disk worked. In my case, I had 931.19 GB on the old disk, and made the new partition 931.3 GB.

    To save time on the second try, I moved both disks inside my old Power Mac G4 (733 MHz) and used that machine to do the copy (it has a SATA card in it). Despite the much older machine, the SATA copy and verify only took 6 hours – really shows what a bottleneck USB2 is! I then attempted to resize the partition on the new disk, still in the G4. After some time, I got all kinds of verification errors and the new disk was essentially unusable.

    A little research found this post and associated replies: http://www.macgeekery.com/tips/cli/nondestructively_resizing_volumes#comment-832

    Apparently PPC Macs can’t resize partitions. I can’t imagine why this is – obviously they can’t boot from GUID partitions, but writing it to disk is just bits and bytes like anything else. And if they really can’t do this, why doesn’t Apple disable that option on PPC machines to avoid corruption?

    Anyway, one more reformat and restore later (yay, another 6 hours), I moved the new disk back to its external enclosure on the Mac mini BEFORE resizing the partition. I successfully resized the partition on the Mac mini, and I’m now enjoying more backup space. ;)

    So if you have a PPC Mac and need to do the resize trick, be aware that you may have to find an Intel Mac to complete that last step.

  30. rolfje Says:

    Mike, thanks for that valuable piece of information! I have both Intel and PPC Macs, and I will sure remember this when I have to upgrade to a bigger TimeMachine drive on the PPC’s.

  31. sandrar Says:

    Hi! I was surfing and found your blog post… nice! I love your blog. :) Cheers! Sandra. R.

  32. folp Says:

    thank you so much! i had 1tb of tm backups to move and it worked flawlessly!

  33. carol Says:

    Marvelous–couldn’t have done it so smoothly without this!

  34. Lu Says:

    Very helpful. Thanks, Rofje! Btw, it took me 16 hours to copy a 1 TB harddrive to another with USB!

  35. Kishore Bhargava Says:

    Great post! Was able to move from a 320GB to a 1TB without any issues. Of course, the only downside being it was slow as hell. Must have been at least 5 hours. But I guess we can blame the USB for that.

    Thanks.

    Cheers…Kishore

  36. Sam Vilde Says:

    Help please?

    I did this and it worked perfectly (thank you). My big drive now has the former name of the smaller drive, and the smaller drive has been cleaned and cleared and has a new name. Time Machine knows the big new drive and backs up to that. But last night I plugged in the old drive, the small drive, and time machine woke up and tried backing up to that one. Shouldn’t it know better? How can I tell it to never back up to the small drive – Time Machine should only wake up and back up to the big new drive?

    Thanks.

  37. Espen Says:

    Hello again! I’m considering moving to a Time Capsule. Anyone here who has tried migrating their TM history to a Time Capsule disk?

  38. rolfje Says:

    After you move timemachine to a new disk, you need to wipe and rename the old disk to prevent TimeMachine from backing up to that disk. Throwing a folder into the Trashcan will not work.

  39. Sam Vilde Says:

    Ok – thought I did that, but I’ll try again. Thanks for your help.

  40. Geoff Says:

    Thanks for the great post. It worked like a charm.

  41. Eve McGivern Says:

    I don’t understand how the partition can be extended without erasing data already on the drive?

  42. Eve McGivern Says:

    Although I think I just figured it out, if the trick to delete the unused partition, then drag down the used partition in Disk Utility.

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