4TB HD Won't Partition

Discussion in 'Mac Pro' started by Average Pro, Oct 25, 2013.

  1. Average Pro macrumors regular

    Jul 16, 2013
    I installed a new WD 4TB Hard drive on my MP (3,1). It appeared on boot up, and I got the auto initialization pop-up which directed me to the Disk Utility. All of the buttons, under Erase and Partition were available, but when I tried to partition it (1 partition), it gave me an error. I then tried to erase it and got the same problem. I rebooted but the problem was still there. Keep in mind, I could see it on my desktop as well. A quick ring to apple to determine if a 4TB drive causes problems. The tech wasn't 100% sure, but stated that an upgrade to Mavericks would more than likely solve it.

    As it turns out, I have one of those external drive boxes (FW800), so I dropped it in there. I was able to partition it and based on the Apple techs suggestion, I re-installed it in my MP and it worked. I haven't upgraded to Mav yet. Maybe tomorrow.

    I did a search and the closest thread I found is listed below. Anyone else run into this?

  2. wonderspark macrumors 68040


    Feb 4, 2010
    Just goes to show how full of BS the Apple techs can be.

    This thread talked about the same issue with 3TB HDDs.
  3. N19h7m4r3 macrumors 65816


    Dec 15, 2012
    Hmm, I was planning on buying two 4TB drives for my MP.

    I think I'll hold off for a while.
    It's hard to believe such an issue exists on "the worlds most advanced operating system". :/
  4. westrock2000 macrumors 6502a

    Oct 18, 2013
    If your not afraid to open the Terminal, I assure there are tools that can get just about anything working.

    Having a Unix terminal alone makes it very powerful.
  5. N19h7m4r3, Oct 26, 2013
    Last edited: Oct 26, 2013

    N19h7m4r3 macrumors 65816


    Dec 15, 2012
    Quite true, but for an OS where things "just work", it's kind of annoying.

    I'll see what happens though.
  6. linkin-ns macrumors newbie

    Apr 19, 2011
    I got a Seagate 4TB, plugged it in, Erase it and it works, but I didnt try to partition it, not sure that help you or not, sry bro :D
  7. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    The Apple tech is correct. There is a known issue trying to format larger than 2TB drives mounted internally with Mountain Lion. Take the same drive and put it in an external enclosure and it formats fine.

    I have no idea if this was fixed in Mavs.
  8. haravikk macrumors 65816

    May 1, 2005
    I seem to remember there being an issue with drives that use a 4k block-size, as I had this exact same problem with a 1tb WD Green drive, but popping it in an enclosure allowed me to format it without any issues.

    It was a while ago though so I don't really remember the exact error, although actually I think I partitioned it without an issues, but it was Core Storage that was giving me the problems, but I did have to re-partition in an enclosure before I could get Core Storage to play nice again.
  9. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA

    I have a standard Seagate ST4000DM000 4TB drive in my 5,1 Mac Pro which is partitioned into 2 2TB drives, one as part of a Fusion drive with a 512GB SSD, and one as a "Media Storage" drive. I don't recall, but I may have initially formatted the drive on an external eSATA dock, but I know I did the partition while it was on the Mac Pro sled. It has been working great 24/7 for the past 6 months in that configuration.

    This was using Mountain Lion OS X
  10. wonderspark, Oct 26, 2013
    Last edited: Oct 26, 2013

    wonderspark macrumors 68040


    Feb 4, 2010
    Guess I can't speak for installing under Mountain Lion, but I installed my 4TB Hitachi HDD in bay 4 under Snow Leopard, two OS's before ML, and didn't have any problems at all. It still runs fine as a single 4TB drive volume after updating to ML.

    Edit: So after looking into it, I read that this glitch was introduced in 10.8.4, so just go back to your 10.8.3 or earlier clone, fix it the way you want it, and then return to 10.8.5 or whatever, since it will still work once it has been formatted. Mine survived 10.8.4 and 10.8.5 without any issues.
  11. AidenShaw macrumors P6


    Feb 8, 2003
    The Peninsula
    A bit of info that may be related, or maybe not.

    A traditional "MS-DOS" partition table has 32-bit unsigned fields for sector numbers - which limits it to disks of no more than 2 TiB. (4G 512 byte sectors)

    GPT (GUID Partition Table) partition tables are required for disks with over 2^32 sectors to use data above the 2 TiB boundary.

    Disks larger than 2 TiB have to be formatted with GPT partition tables to use all of their space.

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