Time Machine drive unmounted during backup and immediately remounted... ??

Discussion in 'iMac' started by StephenCampbell, Oct 11, 2013.

  1. StephenCampbell macrumors 65816

    Joined:
    Sep 21, 2009
    #1
    My 4TB OWC Mercury Pro suddenly unmounted about 600GB into my 2.02TB initial time machine backup. This brand new drive had flawlessly transferred 1.2TB from my Mac Pro via FireWire, and then transferred that same 1.2TB via USB 3 onto the iMac.

    It was plugged into the same port for the Time Machine backup.

    After that incident I erased the drive, switched USB ports and began the backup again.

    I was away for over six hours, and when I came back it appeared that the backup had completed successfully this time... but I don't know for sure if it didn't unmount while I was away and somehow remount and appear to successfully finish.

    In any case the event was highly disturbing and I'm unsure about whether I should trust this drive, or my iMac for that matter (could it have faulty USB ports?)

    What would you do?
     
  2. alksion macrumors 68000

    alksion

    Joined:
    Sep 10, 2010
    Location:
    Los Angeles County
    #2
    Wasn't there just an update for this issue released from apple?
     
  3. StephenCampbell thread starter macrumors 65816

    Joined:
    Sep 21, 2009
    #3
    Oh, is this a known issue? So I don't have to worry about anything being corrupted?

    I was starting to worry that if this drive is dying, that even the massive transfers I did earlier which went with no hitches may have somehow corrupted the data along the way.

    I just realized I don't have 10.8.5 installed yet. Is that the update you're talking about?
     
  4. StephenCampbell thread starter macrumors 65816

    Joined:
    Sep 21, 2009
    #4
    Okay so, assuming it happened because I didn't have 10.8.5, what would you do in my situation now?

    Do I trust the integrity of the 1.2TB of data that I put onto that drive from my Mac Pro and then dumped on my iMac? Both transfers went perfectly and everything seems to be in order.

    Much less difficult to re-do, I could, after having installed 10.8.5, erase the external drive again and re-do the initial time machine backup. The backup did appear to go perfectly the second time I did it, but I was not around as it was happening so I don't know if there was any funny business along the way. Would you erase and re-do time machine post 10.8.5?
     
  5. alksion macrumors 68000

    alksion

    Joined:
    Sep 10, 2010
    Location:
    Los Angeles County
    #5
    I would assume so if it is a brand new drive. Hard drives can come DOA or with bad sectors out of the box, but it isn't common.

    Run a hard drive test like HD Tune in a Windows partition or virtual machine to check for bad sectors or simply verify the disk with disk utility.

    Would I personally do it? If time wasn't a problem and the thought of not having backed things up properly was continuously bothering me, then I might just do it again.

    You got nothing to lose by doing it, but may lose something by not doing it again.
     
  6. StephenCampbell thread starter macrumors 65816

    Joined:
    Sep 21, 2009
    #6
    Well I can't re-do the 1.2TB transfer from my Mac Pro again at this point. If those transfers went without a hitch there isn't really a way data could have gotten corrupted, right? I mean, the little window with the bar of progress went through the whole thing and it finished, and all the data appears to be intact.

    And the problem with re-doing Time Machine with the hope of verifying that it goes through the whole thing with no glitches is that I'm never at home and awake for 10 hours non-stop, so I can't just take a day off for that purpose.

    I just realized though, I don't think it could have done the unmounting/remounting while I was away, because that "the hard disk was disconnected improperly" message shows up, and that doesn't go away by itself, you have to press "OK" or something. So I think it's probably fine.
     
  7. alksion macrumors 68000

    alksion

    Joined:
    Sep 10, 2010
    Location:
    Los Angeles County
    #7
    Looks like you already answered your own question then.
     

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