5 Replies Latest reply: Aug 2, 2012 8:12 AM by LitterMines
LitterMines Level 1 (0 points)

Hi all,


A few days ago, I took the Mountain Lion plunge and after performing all the preliminary data copying to external hard drives as well as on last Time Machine backup to my dedicated Time Machine external hard drive, I booted from my ML recovery USB thumb drive, reformatted the internal HD, and proceeded to perform a clean install of OS X 10.8.


The ML install and initial setup completed without a hitch, and I had no difficulty in reconnecting to my existing Time Machine EHD and performing an initial backup of the freshly upgraded Mountain Lion system. It took several minutes in the "preparing backup" phase; but once it got through that, it backed up my entire system (which was basically nothing more than the new OS and iLife at this point) within an hour or so.  Time Machine has since worked reliably in performing the automatic backups every hour.


But here's the problem:  My backup history went back all the way to March 2011 before the ML upgrade, and it still (sorta kinda) does now.  However, although I can see all of the backup history tick marks when I enter TM, the ONLY SELECTABLE backups are from the point where ML was installed and onward.  The previous Lion and Snow Leopard backups are visible; just not selectable.  I also verified that the physical backup folders are still present on my TM EHD dating all the way back to last March.  I ran a verify and repair operation on the TM volume, and it came back clean.  I have disconnected and reconnected the TM EHD to TM and of course rebooted, but no joy.  TM did not force me to "start over" with a new backup as some posters have complained of. And it seems to be working fine otherwise.


Has anyone else had a similar experience after upgrading to ML?  Any thoughts on how I might reconnect to my TM backup history?


Thanks in advance for your thoughts.

iMac, Mac OS X (10.6.8), 27 inch Core i5 (mid-2010)
  • Steve Holton Level 4 (1,025 points)

    You may have an issue with user accounts.

    If it thinks that the user account on ML is somehow different than it was before this could be the issue.


    This might be helpful: http://pondini.org/TM/E2.html


    Did you use Migration Assistant for the transfer?

    If so you might want to consult this http://pondini.org/OSX/MigrationProblems.html

  • Pondini Level 8 (38,740 points)

    When you erase a disk, it's treated as a different one for most purposes.


    Sounds like either you didn't use an automated OSX facility to put your data back, or it didn't leave a "trail" for Time Machine to know what happened.  If it had, Time Machine would have automatically "associated" the "new" disk with the old backups.


    The old backups are treated as if they were made from a different drive, that's no longer connected.  You should be able to see them via the procedure in #E2 of Time Machine - Troubleshooting.


    You may be able to get Time Machine to do the "associate" manually, via the procedure in #B6 of the same link.

  • LitterMines Level 1 (0 points)

    Okay, problem solved albeit much to my chagrin as this was a text book case of operator error.  In doing a clean install, I of course had to create a new user account, and for a variety of reasons I decided to reincarnate myself with a new and different username. Mr. Pondini's "Some backups are faded-out and not visible" section in the #E2 section of his Time Machine Troubleshooting guide from his previous post hit the nail on the head.  Thank you! 


    As it turns out I since I entered TM with focus on a folder within my new "home" folder structure, which obviously didn't exist in my pre-upgrade backups, only the POST-upgrade history was selectable.  Apparently I was overtaken by stupidity and didn't think to click out on the top level of the HD (of which I had retained the original volume name). Had I done so, I would have seen all of the back history come to life; and consequently I wouldn't be typing this mea culpa right now!


    So, Time Machine behaved exactly as it is supposed to.  I simply was unaware of that particular TM behavioral detail.


    Now with all that said, the fact that I DID fully erase and repartition my original Lion HD to do a clean ML install then if I read the #B6 information correctly, it sounds as if I should have ended up in a bit of hot water regardless and would have needed to go through the "Associate an OS X Hard Drive" procedure in order to get "reconnected" to my previous TM backups.  Howerver, operator error notwithstanding, TM connected to my backup history without missing a stride as soon as I booted ML for the first time.  So, is it possible that something has changed [for the better] in ML eliminated the need to "reconnect" to existing backups under these circumstances?

  • Pondini Level 8 (38,740 points)

    How did you put your data back after the erase?


    If you used either Setup Assistant or Migration Assistant, even if only to transfer 3-rd party apps and no user accounts, that left a "trail" of what happened, so Time Machine treated the drive as the old one.


    The reason you can't see the backups of the old home folder from the new one is simply that they have different names. 


    You'll see the same thing if you rename a normal folder; it gets backed-up again, and the backups of the new one are completely separate from the backups of the old one.

  • LitterMines Level 1 (0 points)

    How did you put your data back after the erase?

    I didn't, or rather I haven't yet.  Basically, all I have done so far is:

    • Reformat Lion HD and install ML clean from USB thumb drive
    • Run through initial virgin boot setup, e.g. enter my Apple ID and desired user account info
    • Change a few preferences (the "use right side of mouse for secondary click" setting first and foremost!)
    • Configured Time Machine to use pre-existing Time Machine Backups EHD and let it do initial backup (which it simply added on to the existing backup history as I had hoped)
    • Drag-and-drop copied my saved iTunes library (~50 GB) from my ext. FW drive to my new Home Music folder and confirmed that iTunes was working and able to sync with my iPhone and iPad
    • Installed the iLife suite from my Bundled Applications DVD and then updated those apps via the App Store


    Obviously the iTunes folder is an exception to "I haven't yet", but basically, the Lion's share (pun intended) of my previous data has not yet been copied back from the temporary storage on the EHD.


    The reason you can't see the backups of the old home folder from the new one is simply that they have different names.

    Yes, I know that now.  Everything was fine all along.  I just didn't realize that TM [quite sensibly] grays out any backup history finder windows and right-hand-side tick marks that contain no backup of the folder currently in focus.  Since the folder I had in focus was one that didn't exist before I installed Mountain Lion, there was nothing to access except for the most recent post-upgrade backups.


    Thanks much for your help.