How can I reuse a Windows hard drive as an external Mac hard drive without losing my data?

December 4, 2006 1:14 PM

How can I reuse a Windows hard drive as an external Mac hard drive without losing my data?

I have a Windows machine with an additional hard drive on which I have 140GB + of media files. I want to get rid of the machine altogether and use that hard drive, in an enclosure, as an external hard drive with my Mac (via USB connection).

I know Windows uses NTFS, which mounts as read-only on a Mac, so I would need to change the file system type.

Can I do that without doing any kind of formatting? I don't have 140GB available on my mac, so I would have to burn 30 DVD's, which I'd obviously like to avoid.

In other words, is there a Mac utility I can use to convert the hard drive from NTFS to HFS?

posted by frenchbenj to Computers & Internet (6 answers total)

Response by poster: The hard drive in question has a 250GB capacity, so I could deal with a solution that involves partitioning it in two volumes, one NTFS and one HFS+ and copying the data (if only, of course, i knew how to do that...)
posted by frenchbenj at 1:16 PM on December 4, 2006

i don't know if you can change your drive's format, but if you can share the drive on a network via smb, you can use your mac to write to it - i have done this and it works.
posted by sid at 1:22 PM on December 4, 2006

Generally speaking, the piece of software you want in order to do this is a "soft partitioner" (sometimes called "dynamic partitioner"). Back in the pre-OSX days there used to be a few Mac programs that did this, but now I can only find one, and it's one I don't have any experience with: VolumeWorks. It's going to set you back $60, and you'll probably want to contact them directly to make sure it'll work with NTFS.

They have all sorts of disclaimers telling you not to use it on a drive that you haven't backed up first, which is probably good advice. Soft formatting always had a bad reputation for causing problems and instability; I never thought of it as more than a temporary fix.

There might be some tools on the PC side that would let you dynamically reformat the drive into two partitions, one NTFS and another FAT (which OS X will handle without problems) and then reformat the FAT part to HFS+ on the Mac ... but honestly I think you would be a lot better getting another hard drive (a 160GB is under $50 on Pricewatch right now), mounting the NTFS drive as read-only, and copying your data. Particularly if you don't have backups of the drive (and if you do, why not use those to copy the data?) playing around with dynamic formatting is dangerous.
posted by Kadin2048 at 1:35 PM on December 4, 2006

Seconding just buying a second drive.

There are some pretty reliable Linux-based tools (bootable from a Live CD, so you don't need to install anything on your machine) that will let you shrink your NTFS filesystem to its minimum possible size, then shrink the partition that the filesystem lives on down to that size so you can allocate more partitions on the same drive. I can post instructions for how I'd do that if you want, but doing major maintenance on 140GB of anything without a backup is asking for trouble, and if you have another drive to put a backup on, you don't need these tools.

BTW at least in Australia, 320GB drives are currently the best value in cents per gigabyte.
posted by flabdablet at 2:57 PM on December 4, 2006

I agree with the buy a new drive people. On the other hand, there isn't really a reliable way to re-partition a drive w/o risk to the data. Does a friend have extra disk space, or does the windows machine this is coming from have an extra disk? In that case you can temporarily save the data off, reformat the drive, and move the data back.

That is typically what I do when I need to reuse a disk. I would also suggest to move the drive to FAT32 if there is any chance you want to use it on a windows box again (even just plugging into a friend's computer). OSX handles FAT file systems just fine, and retains the windows compatibility. The only down side is that FAT32 has built in limits to the filesystem (size and individual file size) that can be annoying to run into.
posted by cschneid at 6:21 PM on December 4, 2006

And you are more likely to hit the FAT32 2GB filesize wall with multimedia files than with just about any other kind.
posted by flabdablet at 7:47 PM on December 4, 2006