13 Replies Latest reply: Jun 13, 2015 3:20 PM by IndelibleDream
Kwopau Level 4 (1,730 points)

My External Hard drive is set in NTFS format (as I have used Windows before migrating to Mac). I am trying to figure out how to format my External Hard drive to the format that Mac OS X can read and write. I'm trying to use my External Hard drive as my Time Machine and need to find a way to format my external hard drive so that it can be readable and writeable. Any solutions? Thanks.

MacBook Pro, Mac OS X (10.7), MBP 13 inch 2011
  • FP_iMacAddict! Level 2 (390 points)

    Disk Utility will do it. Mac OS extended works well.

    You're a level 4, and you haven't formatted a drive yet??? Wow!

  • Kwopau Level 4 (1,730 points)

    Just because i'm a level 4 doesn't mean anything. I've been mostly on iphone and ipod part of the discussion. This is my first time owning a Mac OS X, prior to this, i've been mostly on Windows. So excuse me for not doing much on Mac part, but I'm still learning as I on my mac. Thank, that did the job.


    Message was edited by: Kwopau

  • steve359 Level 6 (13,367 points)

    Just did this myself for a 1 TB WD block drive that has Windows and Linux (non-macosx) data.


    DiskUtility is how it worked for me, after saving data from the two partitions.


    The key idea here is to convet the extenral drive from a MasterBootRecord (MBR) partiionmap to a GUID partion map.


    Online documentation for GUID (http://www.ibm.com/developerworks/linux/library/l-gpt/index.html is one) tells how GUID creates a baseline 4-part partion map to create partitions for compatibility with non-GUID-compliant systems while having the other partitions for newer OS.


    In short I did this:


    • Saved my data from the existing partitions
    • Used DiskUtility to partition to a 2-partion disk and selected the "Options" below the disk map picture to make it GUID, with one as MacOS nd one as NTFS. You must adjust partition sizes for this.


    Time Machine will recognize the MacOSX partition, and Windows recognises the NTFS partition.


    Unless you want ONLY a MacOSX partition for TimeMachine and not use the evice for multi-system storage.  Then you let MacOSX keep the entire disk.


    Descurvive enough, but you end up with a multi-OS-compatible drive.


    Good luck!

  • Toke Lahti Level 1 (115 points)
  • Ash Connell Level 1 (0 points)

    That's a good idea to partition a larger external so that you can use it on two operating systems!

  • Gillia60 Level 1 (0 points)

    You guys are awesome

    It took seconds to reformat my external hard drive

  • steve359 Level 6 (13,367 points)

    You dug up an old one, back when I was trying to impress people with my technical knowledge, but before I could apply it fully with strategy.


    Partitioning a hard drive is for times when you need parts of a disk to act under different OSes, now.  But there was once a time when the disks were larger than OS could handle.  So partitions were required to use the disks that were larger (for example chopping a 300 GB disk into 160 GB segments).


    And recall that losing a disk loses all partitions.  And that you should not put a critical backup on just one partition of a disk unless you have no option.


    Currently people partition Mac disks to run BootCamp, not just "because".


    That being said, I am glad that the technical advice somewhere in here did solve one of your problems.



  • satishkandukuri Level 1 (0 points)

    That's what am looking for. Great!!

  • PlotinusVeritas Level 6 (14,725 points)

    External hard drives are as cheap as dirt, theres little call to ever even consider (barring special needs) partitioning a HD


    Have a 1TB external formatted in Exfat for read/writes between both PC and Mac


    Have another HD for Time Machine backups


    and (ideally) another (or two) for archiving data for storage and protection.


    "only 2 types of hard drives, those that HAVE failed, and those that WILL fail"

  • Toke Lahti Level 1 (115 points)

    PlotinusVeritas wrote:


    Have a 1TB external formatted in Exfat for read/writes between both PC and Mac


    exFAT is not journaled and IIRC does not have permissions and can be slow when you have power to run more advanced file systems.

    If you have processing power to use more advanced file systems, why use the dumb one?

    exFAT was designed to be used in memorycards in cameras etc. where processing power is low.

  • PlotinusVeritas Level 6 (14,725 points)

    exFAT is not journaled and IIRC does not have permissions.

    If you have processing power to use more advanced file systems, why use the dumb one?



    Wrong on Exfat. Been using a couple Exfat drives for use between Mac and PC for a long time, no worries.


    There is no "dumb" one, only reliability issues at fail, and compatibility issues.... Ive got mountains of hard drives, most are HFS+ (mac osx ext. jour.)



    Exfat speeds are perfectly fine,..........you missed the intent of the post to the original poster.


    Speaking to the OP, the intent was to be stated: 1. small HD for swapping files between Mac and PC (Exfat)....... 2. a HFS+ (mac osx ext. jour.) HD for use as a time machine,......and 3. an archive copy of all vital data stored away.


    FAT32 (File Allocation Table)

    • Read/Write FAT32 from both native Windows and native Mac OS X.
    • Maximum file size: 4GB.
    • Maximum volume size: 2TB
    • You can use this format if you share the drive between Mac OS X and Windows computers and have no files larger than 4GB.


    NTFS (Windows NT File System)

    • Read/Write NTFS from native Windows.
    • Read only NTFS from native Mac OS X
    • To Read/Write/Format NTFS from Mac OS X, here are some alternatives:
      • For Mac OS X 10.4 or later (32 or 64-bit), install Paragon (approx $20) (Best Choice for Lion)
      • Native NTFS support can be enabled in Snow Leopard and Lion, but is not advisable, due to instability.
    • AirPort Extreme (802.11n) and Time Capsule do not support NTFS
    • Maximum file size: 16 TB
    • Maximum volume size: 256TB
    • You can use this format if you routinely share a drive with multiple Windows systems.


    HFS+ (Hierarchical File System, a.k.a. Mac OS Extended (Journaled) Don't use case-sensitive)

    • Read/Write HFS+ from native Mac OS X
    • Required for Time Machine or Carbon Copy Cloner or SuperDuper! backups of Mac internal hard drive.
    • To Read HFS+ (but not Write) from Windows, Install HFSExplorer
    • Maximum file size: 8EiB
    • Maximum volume size: 8EiB
    • You can use this format if you only use the drive with Mac OS X, or use it for backups of your Mac OS X internal drive, or if you only share it with one Windows PC (with MacDrive installed on the PC)


    EXFAT (FAT64)

    • Supported in Mac OS X only in 10.6.5 or later.
    • Not all Windows versions support exFAT. 
    • exFAT (Extended File Allocation Table)
    • AirPort Extreme (802.11n) and Time Capsule do not support exFAT
    • Maximum file size: 16 EiB
    • Maximum volume size: 64 ZiB
    • You can use this format if it is supported by all computers with which you intend to share the drive.  See "disadvantages" for details.
  • Toke Lahti Level 1 (115 points)

    PlotinusVeritas wrote:


    There is no "dumb" one, only reliability issues at fail, and compatibility issues....

    I'd call exFAT a "dumb" file system. A new system in 2010's and it doesn't have journaling and only uses a single file allocation table and free space map?

    But of course you can use it for small temporary use.

    I just wish that the next new modern file system would use the whole feature set that every file system should have.

  • IndelibleDream Level 1 (0 points)

    Perfect!... Thank you