2.2TB Limit and USB in Mac

Discussion in 'Mac Basics and Help' started by Rian Gray, Dec 19, 2015.

  1. Rian Gray macrumors regular

    Rian Gray

    Joined:
    Jul 13, 2011
    Location:
    NJ, United States
    #1
    Sorry if it's not under the right category. I just want to know if it's a universal issue or just happening on my Mac. A couple of months ago, I wrote in another thread about a problem I was having that I couldn't boot my computer with external HDDs attached.

    As it turns out after months of testing, it only refuses to boot when a hard drive beyond 2TB is connected via USB. So if there is a 3TB HDD connected via Thunderbolt, it's perfectly okay. But if there is one connected via USB, then it won't boot. Just halt at the grey screen, and none of the peripherals (I use USB keyboard) will work. The problem persists even on the login screen. I have to wait till I see the wallpaper.

    I did some digging, and it turns out there is such problem very similar to what I'm having. But it only applies to PC. So, what could really be going on behind the screen?
     
  2. JackieInCo macrumors 601

    Joined:
    Jul 18, 2013
    Location:
    Colorado
    #2
    I have a 4TB USB 3.0 external attached to my MBP and it does not have a problem with booting up ever.
     
  3. Rian Gray thread starter macrumors regular

    Rian Gray

    Joined:
    Jul 13, 2011
    Location:
    NJ, United States
    #3
    Could you share the model of your Macbook Pro? Mine is late 2012, 27-inch iMac. Perhaps Apple is using different hardware/software with newer models? I should try it with my Macbook Air.
     
  4. JackieInCo macrumors 601

    Joined:
    Jul 18, 2013
    Location:
    Colorado
    #4
    I have two MBPs:

    Mid 2015 15" MBP
    Mid 2012 13" MBP non retina

    I've used the same external on both without a problem.
     
  5. Rian Gray thread starter macrumors regular

    Rian Gray

    Joined:
    Jul 13, 2011
    Location:
    NJ, United States
    #5
    This is so strange. It works on my MBA, and Mac mini. It's just iMac that gives me trouble.
     
  6. BrianBaughn macrumors 601

    BrianBaughn

    Joined:
    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #6
    And this has been verified with multiple hard drive enclosures of different types?
     
  7. phrehdd macrumors 68040

    phrehdd

    Joined:
    Oct 25, 2008
    #7
    I'll just throw a couple of ideas here -

    Are you using a USB3 external to a USB2 port on your Mac?
    Have you tried plugging in that drive into the USB port that is giving you issues and reformatting the drive?

    What format is that external drive and if it is for Mac, is it journaled?

    There are all sorts of quirks that happen and sometimes they are consistent and sometimes not.
     
  8. JohnDS macrumors 65816

    Joined:
    Oct 25, 2015
    #8
    You don't say what OS you are using. I believe you need OS 10.6 or newer to boot from a drive larger than 2 TB. also the partition map on the drive needs to be GUID, not MBR.
     
  9. Rian Gray thread starter macrumors regular

    Rian Gray

    Joined:
    Jul 13, 2011
    Location:
    NJ, United States
    #9
    Yes I have. I've tried 3 different enclosures and docks.

    It's USB 3, and unfortunately I cannot reformat all of them. I have multiple drives and did try to reformat some of them, but never had a chance to reformat all of them at once. All of them are HFS+, journaled, with GUID scheme.

    I'm using El Capitan, OS 10.11.2. All of the drives are using GUID.
     

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