Can't Copy To An External Hard Drive

Discussion in 'OS X Mountain Lion (10.8)' started by Futhark, Jul 6, 2012.

  1. Futhark macrumors 65816


    Jun 12, 2011
    Northern Ireland
    Hi all, i've run into a dilemma today and i was wondering if anyone else has experienced this issue? When i plug an external hard drive into my MacBook Pro running OS X 10.8 (12A256) i can't copy files or folders to it? when i drag them across the little white circle icon with a line through it appears and it just puts the files back to my desktop? has anyone found a solution how to resolve this? :confused:
  2. NewbieCanada macrumors 68030

    Oct 9, 2007
    Is the drive formatted for Mac or Windows? If it's formatted for Windows (NTFS) you need a special driver for Macs to be able to write to it. If you run the disk utilty, you can check on this.
  3. Futhark, Jul 6, 2012
    Last edited: Jul 6, 2012

    Futhark thread starter macrumors 65816


    Jun 12, 2011
    Northern Ireland
    A fantastic !!! i never thought of that, i'll check it now, it's what ever format it came out of the factory? would that usually be FAT32

    Edit: problem sorted !!! It was NTFS
  4. Arelunde macrumors 6502a


    Jul 6, 2011
    CA Central Coast
    I successfully use an external drive on my MBP that I formerly used on my PC. It works ok on my MBP. I learned that Macs can access PC flash or other drives, but PCs can't access Mac drives.
  5. Sesquipedalian, Jul 8, 2012
    Last edited: Jul 8, 2012

    Sesquipedalian macrumors newbie

    Jun 27, 2012
    Be aware that which format you should choose for your drive varies depending on what you plan to use it for.

    If you plan to use it as a Time Machine backup drive, you need to format it as HFS+ (Journaled). However, you won't be able to use this on a Windows machine without installing extra commercial software on it.

    If you plan to use it as a drive that will be accessed by both Macs and non-Macs, you have two options:

    1) Format it as FAT32. FAT32 is readable by virtually every computer and digital device in existence today. However, FAT32 can only handle files smaller than 4GB; if you try to put something larger on there, the copy will fail. So if you want to put really large files on your drive (big video files, for example), this won't a good option.

    2) Leave it in NTFS format, and install this: NTFS-3G adds NTFS write capability to OS X so that you can use it just as you would a FAT32 drive. Note that there is also a commercial version available from Tuxera that is faster, but for the average user the free version should be sufficient.

    EDIT: more info on options for add NTFS write support to OS X can be found here:
  6. pizzacake macrumors member

    Sep 13, 2006
    You can put files > 4GB on a FAT32 if you create a sparse disk image > 4GB. As this contains bands < 4GB. Just add files > 4GB to this disk image.
  7. idle vice, Oct 15, 2013
    Last edited by a moderator: Oct 15, 2013

    idle vice macrumors newbie

    Oct 15, 2013
    NTFS 3G System Preference plugin

    i use the latest version of tuxera ntfs for mac which enables read\write access to NTFS volumes and avoids all of the ugly FAT32 issues...

    it is a little unstable on older Macs though, so I disable it when not actively wanting it to run.


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