External hard drive with Mac & Windows

JadeNB

Registered
I have an external hard drive (actually an internal hard drive with enclosure) which I want to be able to use with both my Apple and my Windows machine. I partitioned it using the Mac, leaving some free space for the Windows machine, but the Windows machine (running XP) doesn't recognise the partition at all -- just complains that it's uninitialised. Presumably, if I initialise it, that'll wipe out the Apple partition. (It's blank right now, so I'm happy to repartition if and as necessary.) What should I do?
 

HateEternal

Mac Metal Head
I have never experimented with Partitions on External disks, are you sure it can be done?

Also, if you want something that both can use format it in FAT32.
 

JadeNB

Registered
I am sure partitioning can be done, because I did it. Mac OS can see the partitions; it's just that Windows can't.

How do I format in FAT32 using Apple? There is an option to format with `MS-DOS file system', but that seems unsatisfactory (e.g., it only allows 8-character file names).
 

nofupa

Registered
Connect the external drive to your Mac.

From the terminal command prompt, type "diskutil list". Press Enter.

Note the identifier of the external disk. (ex. disk2, disk2s10, etc.) You want the identifier of the main disk, not the subvolumes if any.

Then enter this 1-line command in the terminal at the command prompt:
"diskutil partitionDisk disk2 2 MBRFormat MS-DOS DOSVolumeName 10G HFS+ HFSVolumeName 10G"

I have a 20G drive, each partition is 10G. Adjust accordingly for your sizes. You can also specify volume names.
 

nofupa

Registered
I forgot to mention...substitute the disk identifier of YOUR disk for the 'disk2' the diskutil command.

jp
 

JadeNB

Registered
diskutil partitionDisk disk2 2 MBRFormat MS-DOS DOSVolumeName 10G HFS+ HFSVolumeName 10G

Thanks a lot. I know this is pretty stupid, but which of these are variables and which are constants? I assume that disk2 is the disk identifier, 2 is the number of partitions, MS-DOS and HFS+ are specifying what format to use, DOSVolumeName and HFSVolumeName should have the appropriate volume names substituted and 10G is specifying the size of the partition. What I'd like to do is partition it into three partitions: One HFS+ disk (most of the disk), one FAT32 disk (to transfer things from the HFS+ disk to the NTFS disk) and one NTFS disk. Can I just make three partitions, two of them FAT32, and then repartition one of them using Windows?
 

ElDiabloConCaca

U.S.D.A. Prime
AFAIK, you cannot partition a partition -- it's only "one level deep," so to speak, so the partitioning into three partitions must be done all at once.

I believe you could have 1partition for HFS and then 2 partitions for MS-DOS (FAT32), then just reformat one of the FAT32 partitions to NTFS on a Windows machine.
 

Damrod

Registered
Lardbeetle said:
couldn't you just format into one FAT32 partition? I thought they were cross-platform...
What interest should Apple have in allowing to format FAT32? Providing UNIX-FS and DOS is more then Microsoft offers.

I could imagine it has something to do with copyright issues for licensed tech. that Apple would like to save by not implementing it, as it is not really necessary
 

nofupa

Registered
Yes.

"disk2 is the disk identifier, 2 is the number of partitions, MS-DOS and HFS+ are specifying what format to use, DOSVolumeName and HFSVolumeName should have the appropriate volume names substituted and 10G is specifying the size of the partition."

Above is all correct. All you need to do is create 3 partitions, but create 2 of them using the FAT32 specs.

For example:
diskutil partitionDisk disk2 3 MBRFormat MS-DOS DOSVolume1Name 5G MBRFormat MS-DOS DOSVolume2Name 5G HFS+ HFSVolumeName 10G

Now, once you have created the partitions, you can use Windows to create the logical volumes. At this time, from Windows, you can specify the format (FAT32, NTFS).

HTH
 

JadeNB

Registered
Thanks to the poster who caught me out on misuse of language. Of course I meant `reformat the partition', not `repartition the partition'.

nofupa, your advice worked perfectly. I tried it with format NTFS (which is in the Filesystems folder), but got an error message, after which nothing happened for several hours. I know this is dangerous, but eventually I CTRL-C'd out of it. I had a little difficulty later on -- I had to repartition (I do mean repartition, not reformat) a few times -- with it saying a disk could not be mounted after erase, but trying again fixed that.

Here's the curious thing. I partitioned into a 95G JournaledHFS+ partition, a 10G FAT32 disk and a 45G FAT32 disk (destined to become NTFS). When the 45G disk was at the `end' of the physical disk, Windows refused to format it into NTFS; when I mvoed it to the `middle' of the physical disk, it formatted just fine. Anyway, it all seems to be working now.
 
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