How do you format an external HDD for Mac, Time Machine & PC?

Discussion in 'Mac Basics and Help' started by Minxy, Nov 17, 2012.

  1. macrumors newbie

    Nov 17, 2012
    Hello everybody I hope this is the right place to post my question! I'm new to Macs. :)

    I have a 2 TB external HDD. A PC and a MacBook Air with 128GB SSD.

    I want to create a NTFS partition for PC, a HFS+ partition for Mac and a partition to use Time Machine with my MacBook Air (HFS+ again I guess?)

    I know how to format the HDD on my PC but not on Mac. How do I format the external hdd with the 3 partitions and with the different file systems? Also, I've read I should use more space with Time Machine partition then there is on the Macbook Air. My Air has 128GB how much space should I use with Time Machine, 256GB?
  2. macrumors 603


    Apr 29, 2005
    San Francisco
    You use Disk Utility (it's in Applications/Utilities folder). Plug in your external, it will show up on the side bar, select the drive and hit the Partition tab at the top. The options for choosing partitions will come up. It's fairly straight forward.

    As for your Time Machine partition, I'd say go with a solid 3 or 4 times the MBA hard drive. Maybe around 500gb unless you're going to desperately need the space for your other two partitions.
  3. macrumors 6502a

    Stooby Mcdoobie

    Jun 26, 2012
    If I were you, I'd just set up an exFAT partition to be shared between your Mac and your Windows PC, then an HFS+ partition (Mac OS Journaled, Extended) for Time Machine. This is how my main external drive is set up, and it works well.

    If, for some reason, you don't want to share the partition, your way would work as well. You will have to do the NTFS partition in Windows, as OS X can't natively create NTFS.

    Here is a bit more info on hard drive formats:

  4. thread starter macrumors newbie

    Nov 17, 2012
    GimmeSlack12 and Stooby I just wanted to say thanks for the advice. I used disk utilities and it worked great, and then I attached the external hdd to the PC to slow format the NTFS partition. I also added a program to enable me to choose when Time Machine makes backups. Everything is working great!

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