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insultcomicdog

macrumors newbie
Original poster
Jan 23, 2007
12
0
Hi all...Some newbie questions...

I have a Seagate Barracuda 7200.10 750GB SATA2 3GB/S 7200RPM 16MB Cache NCQ Hard Drive.

I have it separated into two different partitions, formatted as HFS+.


I would now like to share the drive between a MAC and a PC, so I realize have to reformat it as FAT32.


My questions are:

1. Should I reformat the external drive with a MAC or PC? Does it make a difference which system I use to reformat?

2. Is it possible to have two partitions with different formatting, one formatted as HFS+ and one formatted as FAT32?

Thanks in advance.
 

trainguy77

macrumors 68040
Nov 13, 2003
3,567
1
Yes you have have two different formats on one drive. It does not matter what machine you use to format it as fat32.
 

yellow

Moderator emeritus
Oct 21, 2003
16,018
6
Portland, OR
It's actually not easy to format partitions as FAT32. Surprisingly.

Disk Utility on your Mac will only format as FAT32 when it's formatting the whole volume, not a partition. There are ways to do it via the command line, I believe.

Windows has a built-in limitation to only be able to create a 32GB FAT32 volume. A limitation created by Microsoft to encourage users to move to NTFS.

I suggest you get a GPartED cd (google for it) and use that on your PC to split/format the partition as FAT32.
 

insultcomicdog

macrumors newbie
Original poster
Jan 23, 2007
12
0
Thanks for the feedback and link...

I'm new to the Mac, so forgive my newbie questions...

I'm trying to use the command line tool diskutil as per the tutorial "By: moritzh on Mon, Jan 12 '04 at 7:43PM PST".

http://www.macosxhints.com/article.php?story=20030613121738812

This is are the commands I am using but I keep getting a syntax error:

diskutil partitionDisk /dev/disk1 numberOfPartitions MBRFormat <part1Format PARTITION1 349.2G> <part2Format PARTITION2 349.2G>


Can any of you Terminal gurus tell me what I'm doing wrong?
 

yellow

Moderator emeritus
Oct 21, 2003
16,018
6
Portland, OR
This is are the commands I am using but I keep getting a syntax error:

diskutil partitionDisk /dev/disk1 numberOfPartitions MBRFormat <part1Format PARTITION1 349.2G> <part2Format PARTITION2 349.2G>


Can any of you Terminal gurus tell me what I'm doing wrong?

Well, your math is off. A 750GB HD doesn't have 2x349.2GB partitions to give up. A 750GB hard drive is 750,000,000,000 bytes. And there are 1024 bytes in a Kilobyte, 1024 Kilobytes in a Megabyte, and 1024 Megabytes in a Gigabyte. Meaning:

750000000000/1024/1024/1024 = 698.492GB is the ACTUAL size of your external harddrive. Try splitting THAT in 2 to create your partitions and see what pans out.
 

nplima

macrumors 6502a
Apr 26, 2006
606
0
UK
Ext2

While you're not copying anything crucial to that drive yet, you might want to try using EXT2 instead of splitting the drive in half and then formating into FAT and HFS.

I've been using EXT2 on a windows box for over a year and it has been working flawlessly.
http://www.fs-driver.org/

I haven't tried using EXT2 on my mac yet, but the software exists: http://sourceforge.net/projects/ext2fsx/

Since FAT32 wastes more space in proportion with the drive size, using EXT2 to share between OS X and Windows might be a good idea.

Nuno
 

jeremy.king

macrumors 603
Jul 23, 2002
5,479
1
Holly Springs, NC
diskutil partitionDisk /dev/disk1 numberOfPartitions MBRFormat <part1Format PARTITION1 349.2G> <part2Format PARTITION2 349.2G>

If this is the actual command you are using, I suggest you read it A LOT more carefully. You can do some serious damage with diskutil, so I guess I misspoke when I thought it was easy.

I highly doubt your external hard drive is /dev/disk1 - because this is usually the boot drive and I don't think you really want to format that. numberOfPartitions is supposed to be replaced with a number, in your case, the number 2. Also the parts inside the <> were also supposed to replaced with the information you want to use, as explained in the post, meaning once you actually come up with a command its going to look something like this - keep in mind you MUST DETERMINE THE DRIVE ID
Code:
diskutil partitionDisk /dev/disk2 2 MBRFormat HFS+ PARTITION1 349.2G MSDOS PARTITION2 349.2G
 

jeremy.king

macrumors 603
Jul 23, 2002
5,479
1
Holly Springs, NC
Well, your math is off. A 750GB HD doesn't have 2x349.2GB partitions to give up. A 750GB hard drive is 750,000,000,000 bytes. And there are 1024 bytes in a Kilobyte, 1024 Kilobytes in a Megabyte, and 1024 Megabytes in a Gigabyte. Meaning:

750000000000/1024/1024/1024 = 698.492GB is the ACTUAL size of your external harddrive. Try splitting THAT in 2 to create your partitions and see what pans out.

Psst...yellow, 2x349.2 = 698.4GB - aka the ACTUAL size of the drive :eek: ...He actually got that part right ;)
 

insultcomicdog

macrumors newbie
Original poster
Jan 23, 2007
12
0
According to diskutil..... "/dev/disk0" is my boot drive and "/dev/disk1" is my external....

/dev/disk0
#: type name size identifier
0: GUID_partition_scheme *149.1 GB disk0
1: EFI 200.0 MB disk0s1
2: Apple_HFS Macintosh HD 148.7 GB disk0s2
/dev/disk1
#: type name size identifier
0: Apple_partition_scheme *698.6 GB disk1
1: Apple_partition_map 31.5 KB disk1s1
2: Apple_HFS Seagate 1 349.2 GB disk1s3
3: Apple_HFS Seagate 2 349.2 GB disk1s5

I thought it was impossible to partition your boot drive?

I've considered EXT2, but I'd like to be able to use my external drive anywhere without having to install drivers first...I wonder if you can use EXT2 drivers on a PS3??


Thanks so much for the proper code...I'll try the following and let you know how it turns out:

diskutil partitionDisk /dev/disk1 2 MBRFormat HFS+ PARTITION1 349.2G MSDOS PARTITION2 349.2G
 

skinsone

macrumors regular
Dec 27, 2006
126
158
Don't mean to be a thread stealer here but I also have a question concerning an external hard drive format.

I am also a newbie to Mac and just got my MBP and am loving it. I bought Parallels to install XP Pro on this external drive. My external HD currently is FAT32, except the C drive which is NTFS which is where I want to re-install XP Pro using Parallels.

The C drive currently has XP Pro, NTFS, and my question is what format do I use when reformatting it.

I hope I have asked my question correctly. I would like to do it right the first time and not have to come back and ask more questions. Reading this thread has also helped me understand some of this and I have already have the partitions converted to FAT32 using Partition Magic. Oh, the external drive is USB connected to my Vaio at the moment and once I get Parallels installed the external will be connected to my MBP. I just don't understand the steps and the order to do this in.

Thanxs for any help and suggestions ...........
 

insultcomicdog

macrumors newbie
Original poster
Jan 23, 2007
12
0
Worked like a charm thanks guys....I now have two partitions...HFS+ and FAT32...


If I decide later I want to change my gigantic 349.2G FAT32 partion to NTFS, does that have to be done on a PC with say Partition Magic?
 
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