windows 7 - How to format an external hard drive as UDF on a Mac

03
2014-01
  • Nick Klauer

    I have an external USB hard drive that I'd like to format to UDF for cross-compatibility with Windows and Macs. I tried exFAT, but for whatever reason, because of the block size (56KB) of the format, it's eaten up a huge portion of the disk space (~400GB actual data, ~900GB used disk space).

    Is there a utility on Mac OS X to format hard drives to UDF?

    I can't find any built-in to my version (OS X 10.8.2), and mkudffs doesn't appear to be in my $PATH, so I'm not sure where to go from here.

    • Answers
  • Sascha Kaupp

    Using the Terminal, you might be able to format a disk into UDF. I use the following command to format Blu-Ray-Disks:

    newfs_udf -v "Untitled UDF" -r 2.60 /dev/diskX

    You might want to first find out under what device name your actual disk is found.

  • Dan

    Someone did some research into how to format a flash drive with udf so it can be used on as many operating systems as possible. His findings are at http://sipa.ulyssis.org/2010/02/filesystems-for-portable-disks/ and there's a script to format the disk properly at http://sipa.ulyssis.org/wp-content/uploads/2010/02/udfhd.pl_.txt

  • Anton8000

    I only know about ways to do it from Windows, but if you want to format from a Mac, I would avoid it. I would not format a drive into Universal Disk Format since it is mainly read only, and you can encounter some errors. I would suggest formatting it in NTFS seeing as Mac OS X is supposed to be able to see that format now.


    • Related Question

    osx - Formatting an external Hard Drive for Windows using Mac OS X
  • Alan Storm

    I have an external Hard Drive I'm selling. I'd like to be able to deliver to the hard drive to the buyer for it can be used on either Mac OS X OR Windows.

    Is it possible to do this using the Mac OS Disk Utility? If so, which format, partition scheme or other options should I be using?

    Thanks in advance!

    Update: The key part of this is I need to format the disk from OS X. Disk Utility doesn't appear to use the same terminology (FAT, NTFS, etc.) I need to know what options to set in disk utility to give me a drive that's usable on either operating system.


    • Related Answers
  • bcwood

    OS X can read NTFS file systems by using NTFS-3G. I use it on a pair of 500GB external drives that I use for backups between my various OS X and Windows boxes, and haven't had a problem with it yet.

  • Richard Hoskins

    You can format it to FAT, but not NTFS.

  • Alan Storm

    The "out of the box" answer appears to be use FAT32, and deal with the limitations of not having a file larger than 4gb.

    To achieve this using the OS X Disk Utility in 10.5, you'll want to attach your drive, open Disk Utility, select your drive (and not the partition) from the left hand window-pane/menu, and select MS-DOS (FAT) from the Volume Format drop down.

    Finally, as mentioned by bcwood and of possible interest to power users, NTFS-3G is a FUSE filesystem that enables read/write access for NTFS file systems in OS X (out of the box NTFS is read-only in OS X).

  • Joe

    you have to format it in ntfs format. or you can just delete the partition and someone with a pc can format it

  • jrg

    You can use "Disk Utility" to partition and format it for 'MS-DOS (FAT)', but - because of a bug (that's in Mac OS X 10.5 aka "Leopard", anyway) - it won't then format it correctly if the disk is larger than 128GB.

  • valbaca

    Agreed, FAT32 is the way to go. Fat32 cannot hold single files that are larger than 4GB. This can be be a problem for backups and disk images.

  • Darryl Hein

    As Richard said, you'll need to format it as FAT, if you need to format it through OSX.

    But if you can format it with Windows, then I'd recommend FAT32 as it's a big improvement over FAT.

    But, there is also a piece of software that can be run on windows to read Mac disks, called MacDrive.