I've bought an external 4TB HDD. It is this this one. The problem is that my Macbook Air 11" 2013 (with Mac OS X 10.9.2) does not recognize it.

The device is ok. I can use it from other computers with GNU/Linux. But I don't know what happens with my Mac. Disk utils app does not show it in the volumes list, diskutil command either.

  • Do you know what filesystem it is formatted as? Is it NTFS, FAT32, or something else? Did you re-format it when you got it or did you use it as it came? – ScoBe May 24 '14 at 1:07
  • It came with a FAT filesystem, but I've formatted it with GNU/Linux to other filesystems, but nothing works. I've tested some different partitions tables, but Mac OS X does not recognize anything. – sgmonda May 24 '14 at 1:35
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    This is a known bug introduced in 10.8.4 that AFAIK has not been resolved as of 10.9.3: Disk Utility fails to deal with drives (either internal or external) larger than 2.2 TB in size: discussions.apple.com/thread/5247829?tstart=0 – njboot May 24 '14 at 2:37
  • With the drive connected, run the following in terminal and post the output to pastebin.com . Copy the paste bin link in your reply: diskutil list; echo;diskutil cs list; exit – njboot May 24 '14 at 19:01
  • @njboot as you can see, diskutil cannot list my external drive: pastebin.com/J2i80t6V – sgmonda May 25 '14 at 0:04

I had this problem where I couldn't see my external usb hdd with ntfs format in mac os and I tried DiskUtil where it stuck at loading.

None of above worked for me. But I found this piece of command which miraculously made my hdd drive visible in mac:

set devmgr_show_nonpresent_devices=1

Got it from here:


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Many HDD (most) are sold pre-formated in NTFS (windows).

You Mac wont read/Write to it out of the box.

You can format the disk in Mac format (using Disk Utility) but if you have information on it already then you need to teach your Mac to use the NTFS format.

There are 3d party software that would do that.

If you plan to use the external HDD with Mac only the it is recommended to format it in Mac Extended-Journaled mode to ensure no problems of RW will occur in the future.

Here is some reading for you so you can choose:



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  • 3
    If the filesystem was a problem, at least disk utility would show the volume to allow me to reformat it, but disk utility does not recognize my HDD. – sgmonda May 24 '14 at 1:36
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    True. Does it appear in System Information.app's USB section? – Max Ried May 24 '14 at 7:56

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