alekseyfromsan francisco

Q: Mac OS recognizes NTFS as ExFAT

I have an external 2Tb HD with two partitions one for Time Machine and another for Windows, formatted as NTFS. However my MacBook  recognizes the latter as ExFAT, shows only "System Volume Information" and "$RECYCLE.BIN", but not other files I wrote in Windows, and allows writing on the partition as ExFAT! At the same time when I boot in Windows 10, it shows the partition as NTFS and does not show system files (".Spotlight-V100", ".Trashes", and ".fseventsd"), written by Mac OS. This looks weird and I think Mac OS damages my data on NTFS partition.

 

I have the latest version of El Capitan 10.11.3 and Windows 10.

MacBook Pro with Retina display, OS X El Capitan (10.11.2), Windows 10 in BOOTCAMP

Posted on Feb 11, 2016 5:26 PM

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Q: Mac OS recognizes NTFS as ExFAT

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  • by dialabrain,

    dialabrain dialabrain Feb 11, 2016 5:40 PM in response to alekseyfromsan francisco
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    Feb 11, 2016 5:40 PM in response to alekseyfromsan francisco

    FWIW, OSX can only read from NTFS drives natively so it's not possible for it to "damage" an NTFS partition. OSX can read and write to a ExFAT partition. OSX is not going to confuse the two.

  • by Barney-15E,

    Barney-15E Barney-15E Feb 11, 2016 5:43 PM in response to alekseyfromsan francisco
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    Mac OS X
    Feb 11, 2016 5:43 PM in response to alekseyfromsan francisco

    From dialabrain,

    FWIW, OSX can only read from NTFS drives natively so it's not possible for it to "damage" an NTFS partition. OSX can read and write to a ExFAT partition. OSX is not going to confuse the two.

    Which begs the question, do you have any software installed that helps OS X write to NTFS? Perhaps that is the problem.

  • by alekseyfromsan francisco,

    alekseyfromsan francisco alekseyfromsan francisco Feb 11, 2016 5:46 PM in response to dialabrain
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    Feb 11, 2016 5:46 PM in response to dialabrain

    That is exactly the problem - OSX confuses the two.

  • by alekseyfromsan francisco,

    alekseyfromsan francisco alekseyfromsan francisco Feb 11, 2016 5:49 PM in response to Barney-15E
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    Feb 11, 2016 5:49 PM in response to Barney-15E

    No, I do not have any NTFS writing software on OS X.

     

    Again, the problem is not that OS X writes on NTFS, the problem is that OS X confuses NTFS as ExFAT.

  • by dialabrain,

    dialabrain dialabrain Feb 11, 2016 5:52 PM in response to alekseyfromsan francisco
    Level 5 (6,171 points)
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    Feb 11, 2016 5:52 PM in response to alekseyfromsan francisco

    alekseyfromsan francisco wrote:

     

    That is exactly the problem - OSX confuses the two.

    Not possible. It is possible a user could confuse the two.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 11, 2016 7:42 PM in response to alekseyfromsan francisco
    Level 5 (7,527 points)
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    Feb 11, 2016 7:42 PM in response to alekseyfromsan francisco

    You are viewing this info in Disk Utility?

     

    1.

    Reboot into recovery mode, hold cmd+R at startup…

    OS X: About OS X Recovery - Apple Support

    Open Disk Utility - does the volume still show as being formatted ExFAT?

     

    2.

    Reboot into safe mode (hold shift at startup)…

    Try safe mode if your Mac doesn't finish starting up - Apple Support

    Check in Disk Utility to see if it is shown as ExFAT.

     

    Please post your results for 1 & 2.

  • by alekseyfromsan francisco,Solvedanswer

    alekseyfromsan francisco alekseyfromsan francisco Feb 12, 2016 1:29 AM in response to alekseyfromsan francisco
    Level 1 (8 points)
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    Feb 12, 2016 1:29 AM in response to alekseyfromsan francisco

    So I identified the problem. Here are the steps to reproduce.

     

    1) I used DiskUtility to partition the disk.

     

    2) When creating a partition for Windows, I choose ExFAT format.

     

    3) After rebooting in Windows, I deleted the partition and re-created it with Windows Disk Manager and formatted with NTFS.

     

    4) Back in OSX however it still recognized it as ExFAT.

     

    To solve the problem, I re-created the partition with DiskUtility in OSX, but choose "OS X Extended (Journaled)" format in step #2. Then after I rebooted in OSX in step #4, it correctly identified the volume as NTFS.

     

    This is a serious bug in OSX. If I had not noticed it, it could have cost me entire Windows backup data.

  • by dialabrain,

    dialabrain dialabrain Feb 12, 2016 2:11 AM in response to alekseyfromsan francisco
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    Feb 12, 2016 2:11 AM in response to alekseyfromsan francisco

    alekseyfromsan francisco wrote:

     

    This is a serious bug in OSX. If I had not noticed it, it could have cost me entire Windows backup data.

    FWIW, you left out the fact you originally formatted the partition as ExFat. You said it was formatted as NTFS. At any rate, the reason you ran into a problem is because you erased and re-partitioned from Windows 10. Windows 10 has no idea how to write GUID information so as far as OSX was concerned, the partition was still ExFAT since Windows couldn't change the GUID info

     

    Basically, there is no "bug". Only user error.

  • by alekseyfromsan francisco,

    alekseyfromsan francisco alekseyfromsan francisco Feb 12, 2016 2:26 AM in response to dialabrain
    Level 1 (8 points)
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    Feb 12, 2016 2:26 AM in response to dialabrain

    Whatever you call it, it is a bug to me. It is also a bug that DiskUtility shows this partition as "OS X Extended (Journaled)". Luckily OSX correctly recognizes it as NTFS.

  • by dialabrain,

    dialabrain dialabrain Feb 12, 2016 2:28 AM in response to alekseyfromsan francisco
    Level 5 (6,171 points)
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    Feb 12, 2016 2:28 AM in response to alekseyfromsan francisco

    okay.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 12, 2016 8:43 AM in response to alekseyfromsan francisco
    Level 5 (7,527 points)
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    Feb 12, 2016 8:43 AM in response to alekseyfromsan francisco

    dialabrain is actually correct and if you understand how it operates it may help you avoid this mistake in the future.

     

    Windows will not write it's changes to the partition table that the Mac created (GPT/GUID). Windows will use it's own partition table instead (MBR). That will be 'out of sync' with the original GUID partition table. It is valid to have two partition tables (read up on 'hybrid MBR/GUID') but keeping them in sync is not automatic because it can break other installed OS's.

     

    Sorry if it offends you that it isn't a 'bug' but I'm glad you have it resolved.

     

    OS X will continue to label that volume as OS X Extended - that is what the GUID table says after all, just don't try repairing it in Disk Utility!

    Personally I would dedicate one disk to one OS, having conflicting partition tables will confuse recovery if this disk ever goes bad.

  • by dialabrain,

    dialabrain dialabrain Feb 12, 2016 8:47 AM in response to Drew Reece
    Level 5 (6,171 points)
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    Feb 12, 2016 8:47 AM in response to Drew Reece

    Drew Reece wrote:

     

    dialabrain is actually correct and if you understand how it operates it may help you avoid this mistake in the future.

    Gee Drew, you sound a little surprised.

     

    j/k

  • by Drew Reece,

    Drew Reece Drew Reece Feb 12, 2016 9:09 AM in response to dialabrain
    Level 5 (7,527 points)
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    Feb 12, 2016 9:09 AM in response to dialabrain

     

    I'm not surprised, but your gracious 'okay' looked like you could be accepting the 'bug theory'.


  • by dialabrain,

    dialabrain dialabrain Feb 12, 2016 9:12 AM in response to Drew Reece
    Level 5 (6,171 points)
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    Feb 12, 2016 9:12 AM in response to Drew Reece

    nah. I just got tired of trying to explain.

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