[macgyvr64]

I've run into a small dilemma while attemping to "go back" to using Boot Camp with Windows XP Pro after reformatting my Boot Camp partition to dual-boot two copies of OS X. When I reboot off the Windows CD, only the main hard drive is seen, and I'd prefer not to overwrite me entire machine with just Windows.

The drive scheme I was using earlier was one HFS+J and one NTFS. After borrowing that second partition for OS X, it's now also HFS+J. I'd like to get it back to NTFS for Boot Camp, but Disk Utility only offers HFS+ and HFS+J.

What other special magic does the Boot Camp Assistant do that I can't do maually (and have managed to undo by installing OS X temporarily)? Any help would be appreciated!

[ghporter]

Good question. I've had the attitude that Boot Camp "knows what it's doing" and that I don't, and I've been happy with that. Others have felt that they're much smarter than the people who wrote Boot Camp, and they've decided they can simply use Disk Utility to set up whatever partitions they want, and there's nothing else going on in the background. (Yes, that was very snide, and not aimed at you, macgyvr64.)

I would back up my primary OS X installation and start over. It sounds like there's something that you've done to the partition information for the drive that you can't easily undo. What that information may be, and what you've done to it? No clue. But like I said, I figure the folks that wrote Boot Camp had a lot more information about the background stuff than I do.

[macgyvr64]

No offense taken... I just wrongly assumed that the Boot Camp Asistant used the new resizePartition or partitionDisk option of the command-line 'diskutil' tool to resize my boot drive on the fly and format it as something Windows could make use of. I fully expected Windows to discover the scheme and offer to install on the proper partition.

Since Windows couldn't find any partition other than the main hard drive, I figured I could just run Boot Camp Assistant (BCA from here on in) again and use it to properly format the second partition to NTFS or FAT32. Wrong. Upon launching it reports "The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by BCA for installing Windows." It knows that I've messed with its things :-) I read the man pages on 'diskutil' and attempted to format the partition as FAT32 (Windows will let you format to the desired NTFS if it can get far enough as to see the partitions): diskutil eraseVolume "MS-DOS FAT32" Windows disk0s3 The command runs, but notes that the partition could not be made bootable without unmounting the disk (the one I'm booted from). After that, BCA reports "This startup disk is not supported.".

I wonder if I can use diskutil to merge the two partitions back and then re-split it with the BCA like it appears to want to. Perhaps the app also does some EFI trickery to get Windows to see the partitions?

I'd prefer not to reformat the drive completely and reinstall everything, but knowing the complexities involved and limitations enforced, I may have to do just that.


Update
BCA uses neither of those commands, and I was wrong that they're new. The true new, hidden command is 'resizeVolume', which can partition a disk or volume on the fly without rebooting. [a href="http://www.macworld.com/2007/02/secrets/marchgeekfactor/index.php"]MacWorld[/a] has more on the subject. I'll try merging my two partitions (after reformatting the second one back to HFS+J from FAT32) and re-running BCA to et it do what it pleases. If there's no update or response from me in less than an hour, asume I've hosed everything and am reinstalling ;-)

[macgyvr64]

I got it working again. Here's how:

1) Boot the OS X install disc that came with the Mac, and chose a language to install with, but go no further in the install process.

2) When the OS X installer presents the first screen after the language select, open up Disk Utility from the top Utilities menu and highlight the Boot Camp partition. In my case, it was a once-NTFS-but-now-HFS partition.

3) When booted into OS X off the hard drive, Disk Utility only lists HFS+ and HS+J, but when booted off the Install disc, more volume format options are available, including MS-DOS FAT32. Format the second partition using that. You can change the format to NTFS from the Windows setup later.

3) Reboot and hold down Option to get a list of bootable volumes. You'll see the Mac OS X partition and the OS X Install disc. Hit Eject to retrieve your OS X disc and insert the Windows disc. (At this point you could boot back into OS X off the hard drive and use BCA to merge your partitions back into one) Click to boot the Windows CD.

4) Go through the initial Windows agreements and you'll be presented with a bunch of partitions (my notes in <angle brackets>):
E: Partition1 [Unknown] 200 MB <EFI>
F: Partition2 [Unknown] 133120 MB <Your main Mac partition>
Unpartitioned space 128 MB
C: Partition3 (WINDOWS <the volume name I chose in Disk Utility>) [FAT32] 19052 MB
Unpartitioned space 126 MB

As you can see, there are a few unused partitions, but they're of negligible size.. 126 and 128 MB. EFI also occupies 200 MB, but that's been there from the beginning (I assume it's part of the GPT scheme...)

5) Choose to install Windows on the FAT32 partition you formatted earlier. BE CAREFUL AND READ. Choosing the wrong partition could blow away your entire Mac OS as well, and require you to reinstall everything.

6) Windows will ask if you'd like to change the format of the partition. Choosing the NTFS (Quick) option worked, but I'd bet that the "Convert to NTFS" would also do the trick. If you do a plain old non-Quick NTFS format, it will zero-out the data and eat several hours of your life.

7) Finish installing Windows and then boot back into OS X off the hard drive. BCA will run successfully and give you all its standard options (burn a driver disk, merge the partitions, etc).


I hope this helps anyone stuck in the position I was in :-)

[ghporter]

Or use Boot Camp Utility to "restore boot disk to a single partition" and then repartition it with Boot Camp? May take running Disk Utility from the OS X install disc to do some cleanup. But WOW, that was a lot of work!

[macgyvr64]

Originally Posted by ghporter 

Or use Boot Camp Utility to "restore boot disk to a single partition" and then repartition it with Boot Camp? May take running Disk Utility from the OS X install disc to do some cleanup. But WOW, that was a lot of work!

Right, that's effectively what I did, however BCA wouldn't even launch fully and present its usual commands unless the second partition was formatted to FAT32 by Disk Utility (via the Install disc). It complained about things like "volume not supported" and certain formatting (like the error above). It must be checking for a bootable FAT32 or NTFS volume to launch properly. Apparently formatting it as FAT32 from the command line didn't work -- it seemed to require me to not be booted off the source drive, which is why I went the CD route and, thankfully, had success. I'm typing this in Firefox under Windows XP right now! ;-)

[ghporter]

Ahh. That makes sense. Way too many variables for this simple brain to keep in play, so that's why I just use the basics as provided through BC.

Glad you got things cleared up!

[jtrwallace]

man i wish i had known that. i mistakenly installed leopard over my boot camp then tried to use BCA to merge them back to one and since it was no longer in NTFS it wouldnt let me. then i went through a very lengthy process of carbon copy cloning my 10.4 to an external, reinstalling os x on my internal, migration assisting the carbon copy to my fresh install and then using BCA to put windows back on. im dumb

[macgyvr64]

Originally Posted by jtrwallace 

man i wish i had known that. i mistakenly installed leopard over my boot camp then tried to use BCA to merge them back to one and since it was no longer in NTFS it wouldnt let me. then i went through a very lengthy process of carbon copy cloning my 10.4 to an external, reinstalling os x on my internal, migration assisting the carbon copy to my fresh install and then using BCA to put windows back on. im dumb

I was *this* close to resorting to that measure yesterday, but was hoping I could find a better way with some mucking around. Once everything was backed up, I was pretty fearless in my on-the-fly partitioning and formatting ;-)