# Partitioning/Formatting External Hard Drive



## mgmcc (Dec 28, 2006)

I am trying, without success, to partition & format an external hard drive so that the first 40GB can have a bootable backup copy of my MacMini's hard drive (using "SuperDuper") which means using "Mac OS Extended (Journaled)" as the file system and "Apple Partition Map", instead of Master Boot Record, as the Partition Scheme. 

However, I want to be able to use the remaining 120GB of the drive with Windows PCs. This appears only to be possible if the Partition Scheme is set to "Master Boot Record" rather than "Apple Partition Map" (which doesn't give the option to format a separate partition as "MS-DOS File System"), but then the first partition isn't bootable.

Is there any way to have the first 40GB partition bootable with the MacMini and have the remaining 120GB available for use with Windows PCs? The external drive incidentally is a Firewire drive.


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## Satcomer (Dec 28, 2006)

Well the better way to use the drive is format for Mac OS Extended and install MacDrive 6 on your PC.


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## mgmcc (Dec 29, 2006)

Thanks, but with five PCs as well as the MacMini it is more important for me to have Windows accessing the external drive normally than to be able to boot the Mac. The drive will hold "Acronis True Image" backups, which need to be accessible if a PC is booted with a CD and the drive also needs to be accessible when connected to someone else's PC. Formatting the entire drive with the Mac file system is not an option.

I thought it might have been possible to format the second partition as FAT32 using commands in Terminal.


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## bobw (Dec 29, 2006)

Read This and see if it helps.


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## mgmcc (Dec 29, 2006)

bobw,

Thanks for the link. I suspect, as the partitions were created in Windows, that will result in a "Mac OS Extended" file system in one partition and FAT32 in the other, which is what I already have, but that the "Mac" partition still won't be bootable, because the Partition Scheme is Master Boot Record and not Apple Partition Map. 

The problem as I see it is:

- if the Partition Scheme is Master Boot Record, I can have the two partitions formatted differently, HFS and FAT32, but the Mac partition isn't bootable

- if the Partition Scheme is Apple Partition Map, which would be bootable in the Mac, the entire drive is inaccessible in Windows.


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## artov (Dec 30, 2006)

(I have told this already on this forum, so if I remember this wrong, check
archives  )

I have an external harddisk (Lacie BigDisk, 600 GB), which is partitioned
to three: HFS+ for Mac, NTFS for Windows and XFS for Linux. 

I divided the disk to three partitiones using OS X's Disk Util and made each 
partition a Mac HFS partition. Then I connected the disk to my PC, and 
checked the partition types. Then I cleaned the disk and partitioned the disk
using Linux' fdisk into three primary partitions. I marked the partition 
types as

Mac HFS: af
Windows NTFS: 7
Linux: 83

Then I formatted the Linux partition as XFS and connected the disk to Mac.
There I formatted the Mac partition using Disk Util. A couple of times
it (I guess OS X) complained about the other partitions., but then if stopped.
I then formatted the Windows partition on Windows.

(Reason for using Linux' partition tool was that it can mark the type for
what ever, so it could make the Mac partition even if it did not notice it).


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