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A free utility for NTFS writing on Mac OS X 10.6.5?

I'm a MacOS newbie so apologies if this is a dumb question.

I currently have an iMac running Snow Leopard and a Windows 2008 box with its primary HDD set as NTFS. I'm a little confused as to why I can read from AND write to this NTFS drive from my iMac (both machines are on the same domain), however, if I connect an NTFS external HDD, I can only read from it and not write to it. I just wondered what the difference is between these two scenarios?

I will soon need to be able to attach external USB HDD drive to my iMac and write files (larger than 4gb) to it, and then attach that USB HDD to any one of my Windows 2008/Windows 7 machines, again for reading and writing. Can anyone also advise as to what the best approach for this might be?


marked as duplicate by Daniel Beck, studiohack May 7 '11 at 3:01

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

migrated from serverfault.com May 6 '11 at 19:06

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  • No need to apologize for being new to the OS. Only for being too lazy for the search function. You're not the first one with this particular problem, the question I suggested above is just one of quite a few similar possibilities. See the Related section to the right... – Daniel Beck May 6 '11 at 19:19

Mac OS X cannot write to NTFS file system, but can read from it.

You can write to it if it is mounted and shared from the Windows machine, and you are connecting via smb - the Windows machine is doing the writing in this case.

If you need to connect the drive directly to the mac for writing, you'll have to have the drive formatted in FAT. The current version of Snow Leopard will support FAT64 - so that would be the best bet.

If you can't reformat the drive, then there are some third-party tools to allow the Mac to write to ntfs - google for MacFuse.


The reason this works when talking to the Windows server is because the conversation is happening at a higher level than the disk. The Mac is talking to Windows over a CIFS connection, and it is Windows itself that performs the translation from what's on the disk to what gets served to the Mac. When the Mac is talking with the NTFS partition directly, it's doing so at the block level and is a completely different protocol.

In short, by using CIFS to talk to another server to get at data, what data partition was formatted with matters very little.

Mac OS X has very good CIFS support. Its NTFS support is read-only, though. By accessing the NTFS volume by way of a Windows device, you're in essence proxying the access through a device that does speak NTFS and that's why it works.

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