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TimeMachine problems after Logical Board Replacement

A while ago the display on my MacBook Pro 17-inch. went black and I had to give the Mac to Apple for a repair. After the Mac came back repaired and everything working working as before I ran into a big problem and that was that I could not keep on using the previous Time Machine backup. By starting a new one I just would have lost the entire history and so I started to look into a solution. This is may take after I followed the instruction from this site which was not bad:

Attention: well this also works if you bought a new Mac (like it did when I bought a unibody 17-inch laptop) the same way.

  1. Switch off Time Machine in the System Preferences
  2. Now make sure you are root (sudo -s) or prepend all the commands with sudo
  3. Open the System Profiler, go to Network (left column) and then select the Built-in Ethernet and write down its MAC address which has this format: xx:xx:xx:xx:xx:xx (x means 0 to f)
  4. Open a Terminal and go to the directory containing the Backups.backupdb directory
  5. Execute this command to obtain the old MAC address (the name can be found in the System Preferences/Sharing tab):
    sudo xattr -p Backups.backupdb/<Name of the Mac>
  6. Note: if you don’t know the name or it has a lot of space use the tab key to let the Terminal expand the directory name because it just reference the directory where Time Machine stores the backup data
  7. Use ‘ls -la’ to see if you find a file in that format ‘.‘ (without the quotes). If there is no file like that then make sure that you got the right MAC address from the System Profiler.
  8. Now we need to make sure that the Mac is using the new MAC address instead.

    1. First temporary disable the ACLs:
      sudo fsaclctl -p /Volumes/<Name of the Backup Drive> -d
    2. Then rename the . file (or copy it now and delete it later) so that it matches the new MAC address (maybe it is a good idea to backup that file first):
      sudo mv .<old MAC address w/o colons> .<new MAC address w/o colons>
    3. Write the new MAC address the Mac should use ( is somethin like: 00:11:22:33:44:55):
      sudo xattr -w <new MAC Address with colons> Backups.backupdb/<Name of the Mac>
    4. Now check if Time Machine created a new directory (which is more or less empty and probably ends with ‘ 2′). If there is one I would move this away using
      sudo mv Backups.backupdb/<Name of the Mac>\ 2 /Users/<your user name>
    5. Enable the ACLs again:
      sudo fsaclctl -p /Volumes/<Name of the Backup Drive> -e
  9. Eject the Backup Drive (either moving the Drive Icon into the Trash or use the Eject Icon in the Finder)
  10. Unplug, wait a few seconds and plug in the drive
  11. Open System Preferences, Time Machine and click on Change Disk… After that click on ‘Backup Now’ or just wait until the backup starts.
  12. If the backup takes a long time then you probably succeeded.

Cheers – Andy