Why can't this 7GB dmg file go on a 16GB flash drive?

Discussion in 'Mac Basics and Help' started by jsyxx, Aug 11, 2009.

  1. jsyxx macrumors newbie

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    Apr 27, 2009
    #1
    Ok it's like this, i recently bought my Mac and in preparation before i got it i stocked up certain apps i wanted on my Windows desktop, now I have a 7 GB dmg file that won't go on a 16GB flash drive and it's driving me crazy. I just don't know why it can't go, i re-formatted it and it still won't go.

    Is there something I don't know about dmg files? are they actually larger than they appear, if not I need to find another means of transfering this file and all I have is this flash drive, no connector cables or anything like that.

    Is there anyway that a dmg file can be broken down?
     
  2. JGruber macrumors 6502

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    Feb 13, 2006
    #2
    For starters, make sure the thumbdrive is formated in HFS+, and NOT NTFS or FAT32
     
  3. Dan73 macrumors 6502a

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    Jul 30, 2009
    #3
    I'm betting the drive is formatted as FAT, which doesn't allow for files greater than 4GB, or 2GB can't remember which.
     
  4. JGruber macrumors 6502

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  5. MacDawg macrumors P6

    MacDawg

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    #5
    Most flash drives are formatted as FAT32 to be compatible for both Mac and Windows, however FAT32 has a 4GB restriction. In order to use larger files you will have to format it as either HFS+ (Mac) or NTFS (Windows) and use a 3rd party solution to be compatible.

    NTFS-3G will allow OS X to read/write to NTFS (Windows) and it is free

    MacDrive will allow Windows to read/write HFS+ (Mac OS X), but it is not free

    Woof, Woof - Dawg [​IMG]
     
  6. geoffreak macrumors 68020

    geoffreak

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    #6
    FAT32 has a limit of 4GB of any one file's size. NTFS cannot be written to with Mac OSX without using a driver like MacFUSE
     
  7. jsyxx thread starter macrumors newbie

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    Apr 27, 2009
    #7
    Yea, it is in FAT32 but there isn't an option 2 change it, what 2 do?
     
  8. GoCubsGo macrumors Nehalem

    GoCubsGo

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  9. MacDawg macrumors P6

    MacDawg

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    #9
    See my post above
    Installing NTFS-3G will also allow you to format from Disk Utility

    Woof, Woof - Dawg [​IMG]
     
  10. Bill Gates macrumors 68020

    Bill Gates

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    #10
    As an alternative you can use the "split" command in the terminal to split the file into multiple chunks, and then the "cat" command to concatenate the chunks back into one contiguous file. Type "man split" and "man cat" in the terminal to get the proper syntax.
     
  11. jsyxx thread starter macrumors newbie

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    Apr 27, 2009
    #11
    In disk utility, the options for formatting are all in MacOS, will any of these work on Windows?
     
  12. geoffreak macrumors 68020

    geoffreak

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    #12
    Change the partitioning of your flash drive to GUID. You can do this by going to the partition tab in Disk Utility, choosing 1 partition from the dropdown (or however many partitions you want), clicking the options button, and choosing GUID. Now set the partition to HFS+ and your file will transfer over without a hitch.
    This process will erase your flash drive, so back up the data first.

    For a Windows compatible filesystem, instead install MacFUSE and erase the drive to format it as NTFS.
     
  13. jsyxx thread starter macrumors newbie

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    Apr 27, 2009
    #13
    Can u do this on Windows? because the file is on Windows and needs to be trasferred to a Mac
     
  14. Bill Gates macrumors 68020

    Bill Gates

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    #14
    There are free utilities that will do the splitting. You could also use WinRAR to do it, which is shareware.
     
  15. geoffreak macrumors 68020

    geoffreak

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    #15
    No need to split the file, just use a different file system that has no 4GB limit.
     
  16. Bill Gates macrumors 68020

    Bill Gates

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    #16
    If he doesn't need to transfer >4GB files often he's better off just splitting the file. Using GPT will reduce compatibility with older versions of Windows, HFS+ will need 3rd-party utilities to read or write to under Windows, and NTFS requires NTFS-3G to be installed on any system that needs to write to the drive, and it will also be littered with resource forks. Every potential solution has drawbacks, but I think simply splitting the file is the best path to take since it's just a one-time file copy operation.
     
  17. jsyxx thread starter macrumors newbie

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    Apr 27, 2009
    #17
    wow, i'm still really confused but at least I know whats the problem now, thanks 4 all the help guys:)
     
  18. geoffreak macrumors 68020

    geoffreak

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    #18
    You CLEARLY haven't tried MacFUSE. NTFS-3G is crap in comparison.
     
  19. Bill Gates macrumors 68020

    Bill Gates

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    #19
    I'm not sure if I understood your post as intended since it can be interpreted in two ways.

    Clearly you're very presumptuous. I've been using MacFUSE and NTFS-3G since the initial release of both. NTFS-3G works fine. The performance isn't up to that of Windows, but it's fine for day-to-day operations and very stable. If you read my post you would have seen that I recommended sticking with FAT32 and just splitting the file.
     
  20. jsyxx thread starter macrumors newbie

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    Apr 27, 2009
    #20
    If u change the FAT32 to HFS+ or GPT can u change it back 2 FAT32 afterwards?

    Explain the splitting process from a Windows perspective more, i don't know how to do it
     
  21. Bill Gates macrumors 68020

    Bill Gates

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    #21
    GPT is actually the format of the partition table; it's not a filesystem. In any case there's absolutely no need to use GPT. There is no easy way to convert between filesystems, except when going from FAT32 to NTFS, which can be done using the "convert" command from a command prompt within Windows. The only other option is to reformat, wiping all data from the drive. However, none of this is necessary. I've outlined the steps you need to take below:

    Click this link on your Windows PC to download WinRAR for Windows (32-bit). It allows you to create a new archive in the RAR format and also has options to split a file at specified intervals.

    On your Mac, click this link to download UnRarX. It will allow to you extract the file contained within multiple archives, by concatenating the data contained within each individual segment.
     
  22. Makosuke macrumors 603

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    #22
    Not to try and confuse you further, but yes, you definitely can change it back to FAT32 afterwards. As with any other format change, it will require erasing the disk and reformatting it, but so long as you don't mind that, you can reformat as many times as you want.

    Basically, nothing that's being suggested here is permanent or irreversible.
     

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