Does macOS clash with MSDOS FAT?

Discussion in 'Mac Apps and Mac App Store' started by Sciuriware, Feb 3, 2017.

  1. Sciuriware macrumors regular

    Sciuriware

    Joined:
    Jan 4, 2014
    Location:
    Gelderland
    #1
    Hi all,
    suddenly my FAT formatted USB sticks randomly dismount while being read.
    Could it be a macOS issue?
    The problem was solved by re-formatting the sticks as "MAC OS Extended(Journaled)"
    although full access from MSWindows is now a new problem.

    Did anyone experience this phenomenon or am I the last with FAT on macOS?
    ;JOOP!
     
  2. Pakaku macrumors 68000

    Pakaku

    Joined:
    Aug 29, 2009
    #2
    Fat is handled by OSX just fine. Maybe your USB sticks are falling apart.
     
  3. dwig macrumors 6502

    Joined:
    Jan 4, 2015
    Location:
    Key West FL
    #3
    • If it's happening on all 3 of the machines you list then I suspect it is a macOS issue, either universal or specific to the vintage USB controllers in those machines.
    • I would suggest that you try reformatting to "exFAT" and test to see if that is a successful workaround. If so, it will solve the Windows compatibility issue as exFAT has been supported on Windows universally since Vista and many XP installations have the necessary update to add compatibility. Apple added it with OSX 10.6.5.
     
  4. Sciuriware thread starter macrumors regular

    Sciuriware

    Joined:
    Jan 4, 2014
    Location:
    Gelderland
    #4
    If I'm the only victim it just can't be an macOS issue, with regard to the vast user base.
    Pakaku's suggestion puzzles me: what is the lifetime of certain sticks.
    ;JOOP!
     
  5. IHelpId10t5 macrumors 6502

    Joined:
    Nov 28, 2014
    #5
    Although exFAT is a good suggestion I have found that if you use MacOS Disk Utility to format a device as exFAT, then Windows PC will not be able to mount them. However, using Windows to format as exFAT will allow the device to work correctly on either platform.
    --- Post Merged, Feb 4, 2017 ---
    I have used dozens of quality USB flash drives with my Macs an Win PCs over the years and have never once had a problem with a FAT formatted drive. They always mount, in either platform, in any OS version, including macOS Sierra.

    I would suggest that it's time to purchase a new, quality, USB flash drive as a test (SanDisk for example). I HAVE seen many problems with cheap and/or old USB flash drives. It's not uncommon to provide support to end-users that have USB drives that are over 10 years old, or that they purchased from a sale bin, or that they got in a conference gift bag. My advice is always to physically destroy all of these inferior devices and buy a quality new one for < $10.
     
  6. Nermal Moderator

    Nermal

    Staff Member

    Joined:
    Dec 7, 2002
    Location:
    New Zealand
    #6
    I haven't run into that, but it's possibly due to using GPT instead of MBR.

    I still use FAT32 semi-regularly and haven't run into any problems.
     
  7. Sciuriware thread starter macrumors regular

    Sciuriware

    Joined:
    Jan 4, 2014
    Location:
    Gelderland
    #7
    Well, KINGSTON is not an inferior quality product, but these sticks are indeed quite old.
    ... and I thought USB sticks lasted forever ....
    Anyway: no problems with my new sticks (which of course are a lot bigger).
    Thanks for the advices.
    ;JOOP!
     
  8. dwig macrumors 6502

    Joined:
    Jan 4, 2015
    Location:
    Key West FL
    #8
    I could be that the firmware and/or memory chips on the sticks is at odds with macOS. They may be producing read or write errors and macOS will try only so many times to reread or rewrite before it gives up. It could be that macOS's limit for retries is lower than previous releases.

    I would be rather unusual for several USB sticks to begin to fail on multiple multiple installations of the same OS at the very same time. To me, this smells more like macOS "getting bored" while waiting for some old slow USB device or it might mistake some "wait while I sort through the directories to find the next part of this file" message from the USB device for a "I'm done here, let me go" message or that it is less tolerant of errors and rejects the device after only a small number of retries.

    Still, my recommendation is to replace the USB sticks. While they do last a long time (time = a lot of read/write actions and not true chronological time), they will "wear out" and produce the occasional read or write error. If this happens to the directory files (directories are actually special files) then it could produce an error that causes macOS to "spit out the vile tasting thing" (read: unmount the device). Reformatting the stick to any different format will create new directories while normal reformatting to the same format simply tries to empty the directory file without replacing it with new. Such a reformat may be a klug to get a little more mileage out of the sticks, but it is somewhat risky as the old worn memory is still present and will likely bite again soon.
     
  9. Sciuriware thread starter macrumors regular

    Sciuriware

    Joined:
    Jan 4, 2014
    Location:
    Gelderland
    #9
    Good points. Those older sticks were 4Gb and slower.
    My new sticks are 16Gb and about double the speed (says the flyer).
    Another good reason never to rely on just one means of backup.
    ;JOOP!
     

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