The exFAT wonders

Discussion in 'Mac Accessories' started by Mr Gavoni, Feb 5, 2013.

  1. Mr Gavoni, Feb 5, 2013
    Last edited: Feb 5, 2013

    Mr Gavoni macrumors newbie

    Feb 5, 2013
    Now check this out.

    I have a MacBook Pro 15'' 2012 with OS X Mountain Lion 8.2 on one partition and Windows 7 on the other (Boot Camp). I replaced the optical drive with another HDD, in fact I used the original 500GB Macintosh HD as additional HD and installed a new SSD as the main drive.

    Not knowing what to format the original HDD in, I'd read that exFAT would be compatible with both systems, so I proceeded to format it like that, and then I transferred over 300GB (music and other files) on it, confident that I'd've been able to modify the drive from both W7 and OS X.

    Today I was playing some of music on the HDD in OS X and all of a sudden the playback became intermittent, as if there was some glitch. I saved the music I wanted to play on the SSD, and it went fine; but then for some reason I had to restart the computer, and upon reboot, surprise surprise, Mountain Lion tells me that there is disk that needs formatting. I'm like, wtf?

    Well it was the HDD. The partition had become all of a sudden unreadable, so I had to reformat it, thereby losing all the data.

    Now I am (hopefully) recovering the data with Aidfile, which is still running and smoothly too, but - again - WTF. I seem to have read somewhere that exFAT can cause instability cross-platform problems, but this is epic.

    Now I am going to reformat with Mac Extended Journaled and to hell with Windows.
  2. SVTmaniac macrumors 6502

    Jan 30, 2013
    I actually just had the same problem :mad: I had a 1TB external drive that held all my music and backup files. I switched to a new Mac Mini from a PC and wanted to use it on both systems so I transferred all the files from the external to the internal of the Mac Mini. I formatted the external in exFAT and then transferred all the files back to the external. I was able to read and write to the drive just fine on the Mini and I verified all my data was there. I deleted all the files off the internal of the Mini thinking everything was just fine.

    I put the external on my PC and it didn't see the drive at all. It actually showed the drive as having 1TB of unallocated space on it :rolleyes: So then I plugged it back into the Mini and guess what? Nothing. All the data was gone and it said there was no partition on the drive. I lost everything. :(

    I haven't attempted any data recovery on it yet but I doubt it will be successful.
  3. jahno macrumors newbie

    May 17, 2014
    same problem

    i also installed a SSD 840evo 256gb in the primary hardrive bay of my MBP 13" 2012mid.
    i use an adapter for the original 500gb 2,5" harddrive and installed it in the dvd-drive place.

    using now the ssd für OSx lion and win7 via bootcamp, i tried to use the 500gb drive as an exFAT drive for data. but it collapsed recently after 2-3month without problems, saying "the drive needs to be initialised"

    i reformatted it several times, same problem pops up from time to time. (few days or weeks, no specific pattern except that it happens when i switch on the MBP)

    any ideas if it is because of exFAT? or maybe the harddrive or the EFI firmware or the adapter?? i neeeeeed this drive.
  4. MisterMe macrumors G4


    Jul 17, 2002
    I don't know if the your problem and the problems that you are responding to are caused by this, but there is a fundamental problem with exFAT. FAT is an abbreviation for File Allocation Table. The File Allocation Table is the problem. FAT32 and earlier versions of the FAT file system mitigated the problem by using two alternating File Allocation Tables. exFAT uses only one File Allocation Table.

    Even with dual File Allocation Tables, FAT file systems were subject to unexpected data loss. With only one File Allocation Table, data loss on exFAT seems to be only a matter of time. This is why I assiduously avoid exFAT. For my cross-platform hardware data storage needs, I use the free NTFS-3G driver to format my USB thumb drives and other storage volumes as NTFS. With Mavericks, NTFS-3G patched still works. If the time comes when NTFS-3G can no longer be made to work with OS X, then I will switch to a commercial NTFS driver and learn to live with the faster operation.
  5. jahno macrumors newbie

    May 17, 2014
    i just started a test phase with hfs on that drive. lets see what happens.
    id rather check out the paragon drivers for win. but thanks for the 3g tip

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