Possible to format drive for Mac and Windows?

neutrino23 · December 11, 2005 8:22PM

I'm thinking of getting a small, portable FW drive. I know I can format it for either Mac or Windows and that OS X can read a windows formatted disk.

I'm wondering if I can partition a disk and have one partition Mac OS and one for windows? Will Disk Utility do this? Will windows xp be able to see and read the windows formatted partition? Will it do any damage to the Mac OS partition?

I haven't purchased the drive yet so I can't test it. If I can do this I'll get a larger drive. If it can't do this I'll get a smaller one and just use it for transferring files.

Thanks.

chucker · December 11, 2005 8:37PM

Quote:

Originally posted by neutrino23

I'm wondering if I can partition a disk and have one partition Mac OS and one for windows? Will Disk Utility do this? Will windows xp be able to see and read the windows formatted partition?

Yes, you can do that. In addition, you can also format the partition as FAT32, thus enabling both Mac OS as well as Windows (not to mention pretty much any other system) to read and write it.

You may consider this kind of scheme: a 10% partition in HFS+, another in NTFS and finally an 80% partition in FAT32. That way, you can store Mac-specific data, Windows-specific data and shared data.

sevendusted · December 11, 2005 11:15PM

saved this as a doc file...not sure where i got it from, butg it DID work. I was able to install osx on the mac partition and it was bootable on a mac. The mac side is able to see both the mac partition and the win partition. The windows partition was ONLY able to see the windows side. good luck:

1) Determine the device (e.g. /dev/disk1) associated with your disk. I will be using disk1 and rdisk1 in my examples. You can use steps 2 through 4 in the original hint to find the correct number for your disk. Unmount any partitions that are already on the disk (ejecting from Finder is sufficient). These partitions will be deleted.

2) I made two new partitions, one 18GB Mac (HFS+) called "Mac" and one 10G FAT32 (MS-DOS) called "PC":

diskutil partitionDisk disk1 2 HFS+ Mac 18G MS-DOS PC 10G

3) Unmount the newly created partitions (eject from Finder).

4) Get the partition information. You can use the command pdisk in Terminal. Enter l (lower case L) to list a device's partition map and then /dev/disk1. Then q to quit pdisk. Here's what mine looked like:

/dev/disk3 map block size=512

#: type name length base ( size )

1: Apple_partition_map Apple 63 @ 1

2: Apple_Free 0+@ 64

3: Apple_HFS Apple_HFS_Untitled_2 37486592 @ 262208 ( 17.9G)

4: DOS_FAT_32 DOS_FAT_32_Untitled_3 20856304 @ 37748800 ( 9.9G)

5: Apple_Free 0+@ 58605104

5) Now use fdisk to create the master boot record (MBR) so Windows will recognize the FAT32 partition:

fdisk -e /dev/rdisk1

When prompted to initialize the partition table, enter y.

fdisk doesn't actually create any partitions. It just edits the MBR partition table. That's what the information from pdisk is for. The MBR created by fdisk can only contain information about four partitions. The important ones to enter are the Apple partition map and the HFS+ and FAT32 partitions. This means that in step 2, you can create a total of three partitions. The commands for the two partitions I created are:

edit 1

partition id: af (I wasn't sure what partition id to use for the Apple partition map so I just used HFS+)

edit in CHS mode? n

partition offset: 1 (This is the value in the base column for the Apple partition map in the output from pdisk.)

partition size: 63 (from the length column for the partition map)

edit 2

partition id: af (for HFS+)

edit in CHS mode? n

partition offset: 262208 (from the base column for the HFS partition in the output from pdisk)

partition size: 37486592 (from the length column for the HFS partition)

edit 3

partition id: c (for Win95 FAT32L)

edit in CHS mode? n

partition offset: 37748800 (from the base column for the FAT32 partition)

partition size: 20856304 (from the length column for the FAT32 partition)

You can verify what you've entered using the print command:

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: AF 0 0 2 - 0 1 1 [ 1 - 63] HFS+

2: AF 16 82 3 - 1023 192 19 [ 262208 - 37486592] HFS+

3: 0C 1023 192 20 - 1023 254 47 [ 37748800 - 20856304] Win95 FAT32L

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

Nothing is written to the partition table yet so use the write command to do that. Then quit to exit fdisk.

You're done. If you compare this process to the one described by simoncha, you'll see that it's basically the same except that I left out steps 5 and 7 through 10. This is because I was getting "invalid argument" at step 10 and nothing was being written back to the partition table. Since step 10 wasn't really doing anything, the other steps aren't needed.

brady1984 · December 12, 2005 11:50AM

When I try to do this exact thing with my external firewire drive it let's me choose either windows partition scheme or mac partition scheme. It doesn't appear to let me mix and match, am I doing something wrong?

sevendusted · December 12, 2005 4:02PM

Brandy

if you follow those exact instructions posted above, you will end up with a drive that has a mac and pc partition.

This was my first time EVER using terminal on a mac, and i was able to do it...if i can do it, anyone can

justin · December 12, 2005 6:05PM

Quote:

This was my first time EVER using terminal on a mac, and i was able to do it...if i can do it, anyone can

I'm going to ask my ISP to swallow me whole.

Didn't understand a single word of what you typed:

Quote:

1) Determine the device (e.g. /dev/disk1) associated with your disk. I will be using disk1 and rdisk1 in my examples. You can use steps 2 through 4 in the original hint to find the correct number for your disk. Unmount any partitions that are already on the disk (ejecting from Finder is sufficient). These partitions will be deleted.

I think I lost it after 'determine the device...'

Btw - I'm not a member of MENSA either

nofeer · December 12, 2005 7:00PM

just got an iomega fw/usb 250 gb

i have a g3 imac, ibook g4 both running tiger

dell 8100 xp

why can't i use that combo file format, and put each in a folder without partitioning???

do i need to partition??

rocjetblue320 · December 12, 2005 7:23PM

I'd just use FAT32, Its worked perfectly for me.

lundy · December 12, 2005 9:37PM

Quote:

think I lost it after 'determine the device...'

Yes, heh, that's because he forgot this part:

type

Code:

diskutil list

and see what the name of your disk that you want to partition is. For example, here is what my machine outputs for that command:

Code:

Dual-G5:~ lundy$ diskutil list

/dev/disk0

#: type name size identifier

0: Apple_partition_scheme *149.1 GB disk0

1: Apple_partition_map 31.5 KB disk0s1

2: Apple_HFS Tiger 10.4.4 60.2 GB disk0s2

3: Apple_HFS Archive and Storage 30.4 GB disk0s3

4: Apple_HFS Panther 10.3.8 30.4 GB disk0s4

5: Apple_HFS Tiger GM 28.0 GB disk0s5

/dev/disk2

#: type name size identifier

0: Apple_partition_scheme *18.6 GB disk2

1: Apple_partition_map 31.0 KB disk2s1

2: Apple_MDFW 32.0 MB disk2s2

3: Apple_HFS Johnny's iPod 18.6 GB disk2s3

/dev/disk3

#: type name size identifier

0: Apple_partition_scheme *2.2 GB disk3

1: Apple_HFS iDisk 2.2 GB disk3s2

Dual-G5:~ lundy$

So looking at the above list, I see that there is my internal hard drive (disk0), with four partitions, then my iPod (disk2), then my iDisk (disk3). If I were going to follow the instructions above, I would use the string "disk0" since that is the main HD.

nofeer · December 13, 2005 7:28AM

Quote:

Originally posted by ROCjetblue320

I'd just use FAT32, Its worked perfectly for me.

so i don't "have" to partition even backing up both mac and windows??

thanks

trowa · December 13, 2005 2:14PM

another alternative, if you are willing to spend some money, is to get MacDrive. It is software for your PC that allows Windows to read HFS(+) external drives.

It's not bad. FAT32 is kind of an ugly FS (uses mroe space than it needs to). I like to keep my file systems the same if I can. Keeps things simple and easier to backup.

just FYI

neutrino23 · December 19, 2005 6:08PM

Thanks everyone for the replies.

I thought of just using FAT32 but I'm not sure it handles Mac files gracefully.

One other thought is to format the drive for windows then create a disk image on that drive and format the disk image for Mac OS. I just tested this with a USB thumb drive and it worked. Get Info says it is formatted Mac OS Extended journalled.

This way I can use the windows part for gathering files from PCs and the Mac OS disk image part for backing up my PowerBook when I'm on the road.

MacDrive would be an option for a single computer but one purpose of the portable drive is to connect to a variety of PCs. When I do demonstrations I may generate as much as a couple of GBs of data. On our demo machine I'll install a FW card. On customer machines I'll have to live with USB.

To manage this I'm looking at a Kano Surefire - FW400, FW800, USB2.

besddimo · July 10, 2008 6:53AM

Anyone know if I can use this tip tip to create a bootable HFS+ partition and a FAT32 partition on one external drive under MacOs 10.4.11?

Anyone tried it?

cheers

Possible to format drive for Mac and Windows?

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