3TB (GPT NTFS) drive not recognized

[Thor774]

Hi

Have a 3TB Seagate Barracuda XT model ST33000651AS formatted on a Windows 7 machine 3 years ago with one 3TB GUID partition (GPT) using NTFS.

The drive is fully recognized by several Windows machines I have plugged it into using different USB enclosures.

When I was connecting some of my old hard disks today to my MBP (early 2011) with Mavericks using 2 different USB enclosures I got a message on connecting the disk to the Mac that read something like this: This disk must be initialized by Disk Utility. I pick ignore as I was not in the mood of losing 2.5TB of data. When I went into Disk Utility I saw that the disk was shown as a 800GB hard drive.

None of the other 6 NTFS hard drives I tested before this one gave me any problems, but they were not GPT disks, they were MBR disks.

Is it not possible for the Mac to access GPT NTFS disks with partitions >2.2TB that come from a Windows environment? I tried 2 different USB enclosures that worked totally ok under Windows without any success under OSX.

Is it a compatibility problem with GPT disks created on Windows, or maybe with the Seagate disks?

Thanks.

 

[matrix07]

I have 3 TB . drive formatted by Windows. I really want to know the solution.

 

[matrix07]

Is it not possible for the Mac to access GPT NTFS disks with partitions >2.2TB that come from a Windows environment? I tried 2 different USB enclosures that worked totally ok under Windows without any success under OSX.

Is it a compatibility problem with GPT disks created on Windows, or maybe with the Seagate disks?

Thanks.

OP, do you get the answer? If so, please share.

 

[Thor774]

OP, do you get the answer? If so, please share.

Sadly no. I don't know if repartitioning the hard disk on the Mac will help. I cannot test this as there is a lot of data on it. If the disk was empty this would be my first step to try.

I have been doing some more reading and it appears that there is people with disks that are not from Seagate and that are also affected by the same situation.

I have not tried to connect the disk directly to the motherboard with SATA either as this is a MBP.

Still searching for help with this.

 

[matrix07]

Bummer.

Next month when I have Mac mini I'll report to you about my case.

 

[rctlr]

I had a similar problem with a 2TB drive, but I solved this with attaching it to a rather old windows xp machine and shared it over the network with SMB.
The mac can quite happily read it that way. I gradually moved the data around until the drive as free and I reformatted it as MBR FAT32, then put everything back. Then I could plug the drive in locally to my mac.

Its certainly the GPT Table thats causing the problem, as it uses a unique identifier it cannot be moved all too readily between systems. It's not the NTFS partition within the GPT Table, although Macs can only read NTFS natively, even if you used a MBR table.

 

[matrix07]

I had a similar problem with a 2TB drive,

This is strange. I never have problem with 2 TB. before.

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I thought what the heck! I just share my drive to check and sure enough, it's only 2.23 TB on OSX.

But it appears all my files are there though (it's less than 2 TB. atm.)

 

[Thor774]

I have no problems either with disks under 2.2TB. Have tested with several 1TB and 1 2TB disk.

Have not tried to share the disk over the network yet, but this IMO is just a workaround and no a solution.

If I was going to reformat the 3TB disk on the Mac I would surely have used ExFAT instead of FAT32 if I was still looking for Windows compatibility. FAT32 is just too limited for so big disks.

 

[matrix07]

Erase it. all the data gone (was backed up) but got 3 TB. now. I'm happy.

OSX is much easier to work with 3 TB. than Windows.

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Hi
When I went into Disk Utility I saw that the disk was shown as a 800GB hard drive.

This is not the same as mine. I saw 2 partitions and can't erase one 'cause Disk Utilities said there was not enough space so I erase them all at once.