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levmc

macrumors 6502a
Original poster
Jan 18, 2019
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I heard that exFAT is risky in that if you disconnect without ejecting first, there can be a loss of data. Does that mean Mac OS Extended (Journaled) would not have the same problem?
 
Best practices on a Mac has always been to eject the volume(s) before physically disconnecting the device however its formatted. While Macs can read and write to ExFat disks they can’t boot from them. The should only be used if you need the disk to be used with a Windows machine.
 
I heard that exFAT is risky in that if you disconnect without ejecting first, there can be a loss of data. Does that mean Mac OS Extended (Journaled) would not have the same problem?
There's a risk of data corruption any time you disconnect a disk on a Mac without ejecting/unmounting first, regardless of format.
 
Best practices on a Mac has always been to eject the volume(s) before physically disconnecting the device however its formatted. While Macs can read and write to ExFat disks they can’t boot from them. The should only be used if you need the disk to be used with a Windows machine.
Does that mean you can get away with this on a Windows computer but not on a Mac?
 
I think I heard that with other formats if you don't eject first, the files being transferred at the time of ejection could be corrupted but other files will be okay, but for exFAT if you don't eject first, not only files being transferred but existing files can be corrupted too. Is that true?
 
Journaled means the file activity is copied to a log before it is written to the disk. FAT, FAT32 and ExFat aren’t journaled (easier to lose data via unplugging too early/get data corruption in existing files - less overhead) but HFS+ APFS, NTFS on Windows and ext2/3/4 on Linux are all journaled. (safer, but not bulletproof - more overhead).

You never know with a removable disk if all of the data has been written to the disk before you unplug it. Better to issue a command to eject so that the operating system can flush the write buffers and write the rest of the information to disk.
 
This is what I read. It seems like you have to be more careful for a Mac compared to Windows?
Pavlo recommends properly ejecting if you’re using a Mac, because it always uses the write cache feature.

So what bad stuff could happen if you pull the thumb drive out while you’re copying a file to it, or while the write cache is doing something in the background?

The first possibility is that the file you were copying to the USB drive gets corrupted (although chances are the original file on your computer would still be okay). After that, there’s the chance that another file on that thumb drive gets corrupted, too.


The biggest problem would be if you were to corrupt the USB drive itself—the file system metadata could be ruined, meaning the drive wouldn’t know where things are stored.
 
Would using Mounty be a better alternative to exFAT?

However there are stories about data corruption using Mounty:
Tuxera NTFS for Mac ($20) is much better for the task, if you need to write to NTFS frequently. I have found, however, that reformatting flash drives to another file system will destroy their performance permanently. I'd leave NTFS to hard drives.
 
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Thank you. How is Tuxera much better for the task?
It works! It has an extremely simple interface, gets out of your way and just lets you write to NTFS on a Mac. Paragon NTFS for Mac has a much fancier interface (it tries to do too much); I believe it costs more and the customer support with Paragon just isn’t as good.
 
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