os x: copy fails after 4gb

When copying a huge file to a drive you could see OS X freak out with a cryptic error messages. Around the lines of “Copy of file XYZ failed with error -NUMBER”.

One possible reason is that the target drive (maybe a shuttle one) is formated as “MS DOS” not as “OS X Journaled”.
Command-I when having the drive selected will tell you.
The file size during that error message is up on the screen will be pretty exactly 4GB. When you close the error then the file will be gone. Of course nothing get’s logged in the system log. Not sure if the finder has a log.

OS X: great unix. Kinda …

2 Responses to “os x: copy fails after 4gb”

  1. Daniel Says:

    MS-DOS gave us the FAT (File Allocation Table) legacy.
    FAT12 was used on diskettes but we’ll ignore that, FAT16 used on older hard drives, allowing a 2gb partition size and a 2 gb maximum file size. Microsoft then developed the new FAT32, used by Win98 OSR2 and present on all following operating systems, which could have an almost unlimited partition size, but… a 4 Gb filesize limit! (DVD ISO files and intensive home video was not really a problem then).
    From there, MS has now gone down the NTFS road and is not looking back.

    Under NT based systems from windows 2000, you will also find that you can no longer format drives as FAT32 on a partition larger than 32 Gb - you need external tools for that too, or Windows95/98/Me.

    Just for the record, I also found that REALBasic does not allow input/output on files larger than 2 gb, whatever the target OS… but that is a language limitation, and not the OS’s filesystem limitation.

  2. Daniel Says:

    Correction: FAT32 was introduced in Windows 95 OSR2 and not Windows 98…

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