Apple fanboy Wannabe dev

Dec 11

How to enable NTFS write support in Snow Leopard - Sharing files between Macs & PCs

UPDATE: exFAT [aka FAT64] has since been released and is fully supported by:

-Snow Leopard 10.6.5 & up

-Windows XP/Vista after an update

-Window 7

It’s faster than FAT32 and can handle much larger file sizes and capacities. It’s probably the simpler option vs NTFS now. Soon it will be the default format used on memory cards and small USB drives and this will all be behind us. Larger drives will probably still come with NTFS, HFS etc. though; so you may want to reformat it with exFAT/FAT64 if you want to share it between Mac OS X & Windows.

More info at http://en.wikipedia.org/wiki/ExFAT



So now that I have switched to a Mac, I discovered that Macs use a different disk format system than Windows uses. Windows uses what is called NTFS (New Technology File System). So to transfer files between a Mac and a Windows PC (such as friend’s PC), most folks use an external drive that that uses yet another format called FAT32 that can be read by nearly any computer. But it’s an old, slow and limited format that can’t handle any files larger than 4 GB. Screw that.

So I found a better alternative. Just format an external drive as NTFS and flip a hidden switch that enables Snow Leopard to write to NTFS. NTFS write support was apparently dropped in the final release build of Snow Leopard. It turns out the support is still there, but disabled by default.

This way, (as opposed to FAT32) -

  1. File transfers are faster.
  2. Files can be as big as you wish.
  3. Any Windows PC will be able to read it and write to it.
  4. Any Mac will be able to read it.

In case you’re confused there, you should know that Macs can “read” NTFS out of the box. It’s “writing” that we’re going to enable here.

So the only limitations with this approach would be that -

  1. You would have to use this trick explained below if you want to use this same drive to bring to another Mac and write to it and bring the files back home with you (remember this trick only works for Snow Leopard though).
  2. You NEED to always safely “eject” the drive to ensure smooth operation. This will be explained more at the end.

Here’s the workaround:

Basically, it’s running mount_ntfs with read/write option specified. 

Start by running Terminal, which is located in “/Applications/Utilities/”.

This renames the original /sbin/mount_ntfs tool:
sudo mv /sbin/mount_ntfs /sbin/mount_ntfs.orig
(press Enter, then type your system password in, press Enter)

This will create a script:
sudo nano /sbin/mount_ntfs
(press Enter)

Now type this:
(press Enter)
/sbin/mount_ntfs.orig -o rw “$@”
(press Enter)

This will save the script:
(press Ctrl-O, Enter, Ctrl-X in sequence)

Now type this:
sudo chown root:wheel /sbin/mount_ntfs
(press Enter)
sudo chmod 755 /sbin/mount_ntfs
(press Enter)

Verify by typing:
ls -al /sbin/mount_ntfs
(press Enter)

You should see:
"-rwxr-xr-x" and "root wheel"

Enjoy read/write access to NTFS drives/volumes!

Troubleshooting -

You may have to do this again after a Snow Leopard update. So save this for reference.

If it isn’t working for you, it may be that the NTFS partition wasn’t cleanly unmounted previously (e.g. not using safe eject in Windows). To check if this is the case, open Console in Utilities, and go to ‘All Messages’ instead of ‘Console Messages’. Search for ‘ntfs’ and you may come across an error that displays like this:

NTFS-fs error (device /dev/disk3s1, pid 435): ntfs_system_inodes_get(): $LogFile is not clean. Mounting read-only. Mount in Windows.

You need to plug the disk into Windows (XP, VISTA, 7) and do a safe eject. Then the NTFS partition will mount in read/write mode. This is because OS X has no “fsck_ntfs” to repair problems on the NTFS volume to make it “clean” again.

In case you don’t like it, you can restore the original backup by entering this: 

sudo mv /sbin/mount_ntfs.orig /sbin/mount_ntfs

(press Enter)

EDIT - I just found a software alternative called NTFS Mounter (http://ntfsmounter.com). I am about to try it out. It runs as a menubar item on Snow Leopard and will mount an NTFS drive on demand. It’s still not the ultimate solution and has it’s drawbacks as well, but for the newbies, this might be your preference.