Error writing backup dmg to firewire.

in Genius Bar edited January 2014
I have made a backup of my entire home directory into a disk image to be by the Disk Utility's option to create a drive from a folder. I then have it saved onto the hard drive to prevent a loop. It works well and yields a 9.5 gig file. What i want to do is then put it on an external hard drive to be kept somewhere safe (fire proof safe in next room).

The problem comes around the 5th gb when i get an error saying it couldn't write the file. It is a standard run of the mill external firewire drive that have been pretty much okay in the past. Rather than try to explain the error, i have included a screen shot. it is grayed out because i was in the grab program.

Thanks for any help

I'm on 10.3.5


  • Reply 1 of 11
    russsrusss Posts: 115member
    What format is on the firewire drive? If it's Fat 32 then that's your problem. If not then I have no answer.

  • Reply 2 of 11
    Why is there a size transfer limit with fat 32. If it helps, it cut-off at exactly 3.99 (Found that out later)
  • Reply 3 of 11
    According to my googling, fat32 can handle around 32 gigs while fat 16 only does 4. If i reformat with mac os X to ntfs, will it work with winblows XP and 2k?
  • Reply 4 of 11
    Never-mind. I read it wrong/ The max volume is 32 but file is around 4
  • Reply 5 of 11
    russsrusss Posts: 115member
    Fat32 has a file size limit of 4GB. See here.

    From the article:


    With that 4GB figure stuck in my head, I went to my accustomed research tools and found plenty of references to the FAT32 4GB limit. To back up that number, I searched the Microsoft Web site and found numerous articles confirming that the file-size limit on FAT32 is (2^32)-1 bytes, or one byte less than a full 4GB.

    The confusion about FAT file size seems to stem from the fact that FAT16 has a 4GB limit on partition size, whereas FAT32 has a 2TB limit on partition size. A large number of my respondents appear to have confused "partition" with "file."

    I ran into the same problem as you and thought there was something wrong with the file I was copying until I found out about the 4GB file size limit.

    Edit: Oops, too late. I see you figured it out.
  • Reply 6 of 11
    Thanks for your help.

    Do you know if is is possible to reformat my drive to NTFS with mac? How?

    Will it be windoze compatible?

  • Reply 7 of 11
    russsrusss Posts: 115member
    I don't know of any way to format a drive to NTFS on the Mac.

    It wouldn't help anyway because as far as I know the Mac can only read from an NTFS drive, not write to it.
  • Reply 8 of 11
    isn't osX main drive NTFS? I would think it is beciase i have a 11 gig file without a problem
  • Reply 9 of 11
    russsrusss Posts: 115member
    Mac uses HFS+, not NTFS which is Windows only.
  • Reply 10 of 11
    but, if i fornat the drive under windows to ntfs, would it work as an external drive for mac?
  • Reply 11 of 11
    ebbyebby Posts: 3,110member
    Macs can read NTFS, but last I heard, they can't write to it.
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