Lion mysteriously erases SSD partition on external FireWire drive.

I'm not sure whether this is a problem with OS X, my SSD, or my external FireWire drive, so please bear with me.
Recently, I have been having some hardware problems on my MacBook Pro, and decided to send my computer off to be repaired. Before doing so, I took my Corsair Performance Pro SSD (still on firmware 1.0) out of my machine so that I could boot it from my FireWire 800 drive (Oyen Digital Minipro) onto the school computers.
Both times I have tried this (and on different machines!) I was able to successfully load my laptop installation. Then, after a few minutes, everything would suddenly freeze up (beach balls, et al) and I would have to shut down the computer. Afterwards, the system would not let me boot back into the external drive, and Disk Utility in the host OS would show that my partition had been completely erased, and that I would have to reformat the drive and restore from Time Machine.
Is it possible that Lion doesn't like being booted from FireWire drives? My OS X installation is still on 10.7.3 (as I have not had a chance to update yet) so maybe the FireWire driver has been fixed since then? Could this be a problem with my SSD? Or could my FireWire drive be malfunctioning? I have used this enclosure with a non-boot hard drive without any problems in the past.
Sorry this question is so broad, but I am at a complete loss.

In the "Current" Volume Scheme, the 8GB partition is on top. The 85GB is below that. Originally, the 20GB partition was between them. There is no grey mass i.e. free space in the middle.
Is there a grey mass anywhere? top? bottom?
In other words, do the two white sections that represent the active partitions fill the entire block, or is there any other space that's vacant?
All volumes on the drive are/were formatted Mac OS Extended (Journaled). I'm not sure but, I think that corresponds to "GUID"...right?
No, Mac OS X Extended (whether journaled or not) is independent of the partition scheme in use.
The bottom of the Disk Utility window should report the partition format.

Similar Messages

How do I back up my Boot Camp partition to external firewire drive?

I have a 15 GB Windows XP Boot Camp partition (FAT32). I want to back it up to a 120 GB external Firewire drive. (I know the backup won't be bootable). In OX X Disk Utility, I formatted the external drive as MS-DOS (FAT). I planned to do the backup using the Windows Backup utility.
However, when booted into WinXP, Windows will not recognize the external hard drive. I thought I might need to create a FAT32 partion of 32 GB or less on the external drive, but I apparently can't do this in OS X or Windows (since Windows doesn't recognize the drive).
Any suggestions on how to backup the Boot Camp partition will be appreciated. I'm mainly interested in preserving all programs and data. Ideally, a clone could be created that could be restored back to the original partition in bootable form, but from studying this and other forums, it dosn't seem to be easy to do this for a FAT32-formatted volume.

My goal was to create a bootable clone of my FAT32 Boot Camp partition, while at the same time increasing the size of the partition from 15 GB to 32 GB if possible. This is what I did:
1. As suggested in this thread, I used Disk Utility to create a disk image. I formatted it as MS-DOS (FAT), and made it 32 GB in size.
2. Used the Finder to copy all files from my 15 GB Windows XP partition to the new disk image.
The following steps were only to determine if the disk image is a viable backup:
3. Removed the internal hard drive with my original Win XP partition, and installed a new internal hard drive.
4. Used Boot Camp Assistant to create a 32 GB Boot Camp partition on the new internal drive.
5. Inserted my Win XP installation disk and started the Windows installation. Formatted the new partition as FAT32. (I used the long rather than the quick format method--not sure if this was necessary.)
6. Continued the Windows installation to the point of restarting the computer, at which time I used the Option key to boot back into OS X.
7. Used the Finder to copy all the files from the 32 GB disk image to the new Boot Camp partition. (This overwrote a few Windows files installed by the aborted Win XP installation.)
8. Restarted and used the Option key to select the new 32 GB Boot Camp Partition. Windows booted as usual with all files, programs, etc. from the original 15 GB partition. Windows did complain about "new hardware" and required a restart, but all appears normal.
This indicates that the disk image containing all the files from my original Boot Camp partition is a viable backup, and can be used to restore the partition if necessary. I'm not sure if formatting the disk image as MS-DOS (rather than Mac OS extended) was necessary, or not.

Partitioning an external Firewire drive

Hi,
I'm trying to partition an external 150gb Lacie Firewire drive with the Disk Utility under OSX10.3.9 and I've gone through the Erase procedure and DU is telling me I'm left with 149.1gb after formatting.
So now under the partition tab I'm trying to set out the size of each partition and I know these sizes are gonna sound a bit random but bear with me so I want :-
3 partitions of 10gb = 30gb
6 partitions of 8gb = 48gb
1 partition of 71.1gb
After setting, naming and locking the first 9 partitions, when I get to the final partition, which I want to be 71.1gb, DU won't let me set a figure above 16.81gb.
Now I fully appreciate that disk sizes are, to a degree, 'approximate', that after formatting you do 'lose' a few gb's and that each partition will have a filesystem installed on it but where the heck am I losing 54.29gb of storage space from ?!!
I have experimented with fewer partitions and, to be fair, it seems you lose less space with less partitions but is it really the filesystems on each partition eating up that space ?
I'm using HFS+ (journalled).
Many thanks for any help you can give as this has been a real headache today !
Nick

Hi roam,
Many thanks for your continued input into this thread and my apologises for the delay in replying to your last post.
Anyway, I thought I'd give SuperDuper a go and downloaded v2.1.4 as you suggested and must agree that it's very simple to use. The backup took twice as long as my old way of backing up (restoring from the internal drive to the external drive) and I checked the log file for any errors and there weren't any, so all good there.
I again restarted with the option key held down and yet again I'm only ever presented with one drive icon to boot from, not two, so I'm really not sure why this is happening.
However, I've been giving this quite a lot of thought and I've come to the conclusion that if my internal system drive was to suffer a catostrophic failure (I'm touching loads of MDF here as I type that !!) and the drive is either wiped clean or damaged to the point that I replace it, I wouldn't be booting from my Firewire drive anyway, I'd be restoring from it, so I'd insert my install CD and reboot whilst holding down C, I'd then run Disk Utility and restore from my Firewire drive to the new internal drive.
So what I really want is a mirror image of my internal drive which is what my method of restoring via the restore route gives me.
Is that a correct hypothosis of have I missed something ?
Nick

Booting from external Firewire drive--possible?

If I add a USB/Firewire card to my Beige G3 minitower (300MHz), can I then boot from an external Firewire hard drive on which I have installed Panther? A comment by Tina Garfield in another thread seems to suggest this is indeed possible. (I didn't want to "threadjack" that discussion, so I created this new one. I hope Tina sees it and can help me.)
Tina wrote the following:
Having Firewire allows you to have external drives,
which you will be able to boot from, and make
backups and maintenance especially easy.
I was under the impression that the Beige G3 can't see iadd-on Firewire/USB cards until the machine has booted from the internal hard drive. I really hope I am wrong! If it is indeed possible to have the machine recognize the external drive at startup, and there is something I need to do to enable this, please let me know.
Thanks!
GeeKay

Hi GeeKay,
Ditto to everything Grant posted, with an extra reminder to be sure to download XPostFacto 3.1 and not version 4. I believe on the XPF page ( http://eshop.macsales.com/OSXCenter/XPostFacto/Framework.cfm?page=XPostFacto3.ht ml ), the download for 3.1 is a little bit down the page.
If/when you buy an external FW drive be sure it has an Oxford chipset. If the description does not include mention of the the Oxford chipset, I would strongly recommend finding another external drive that does specify this. Our Beiges are very particular about what they will accept for external booting, and the Oxford chipset is a critical component.
Also, I've found, since I do partition my external firewire drives, that I can boot only from the first partition of the external drive, similar to the behavior of our internal drives. In addition, with one of my Beiges, my "helper" disk that I specify to XPostFacto to allow me to boot externally must be the first partition of my internal drive.
I don't believe that you can actually INSTALL to an external drive. I simply cloned my internal drive's system over to the FW drive. This can be done with software such as the free Silverkeeper ( http://www.lacie.com/silverkeeper/ ) or with shareware SuperDuper ( http://www.shirt-pocket.com/ ) which are both great for all backups. I happen to prefer SuperDuper because of its redundancy -- it explains EVERY step before you take it and then, even after you tell it to go ahead, it asks you again to be sure That's what you want to do.
Once set up, however, it is extremely cool, and helpful, to be able to boot externally. If your external drive is dual USB/FW, you will only be able to boot when connected via Firewire. None of the Beiges are USB-bootable.
Hope this helps, and keep us posted,
Tina

Booting os x from *partitioned* external firewire drive?

Hi all,
my internal hard disk (on a 12" powerbook G4 867 mhz running osx tiger 10.4.10) has started acting weird (many people are reporting failing hard drives, and I'm assuming mine is failing too), so I'm preparing for replacing it with a new hard drive.
I've backed up the drive to an external firewire drive (LaCie portable 80 GB firewire drive "Design by F.A. Porsche") using Carbon Copy Cloner with the option 'make bootable' selected.
PROBLEM: I can't boot OS X using my clone on the external drive.
I'VE TRIED:
1. holding down Command-Option-Shift-Delete while booting to bypass the internal drive. (This didn't work: I saw an os 9 icon blinking/alternating with a question mark for a while, and then the computer booted from the internal hard disk.)
2. holding down Option to select the external drive in Startup Manager. (Didn't work either: Startup Manager opened fine, but only showed my internal drive volume. I tried clicking the 'rescan' button, but it couldn't find my external drive.)
3. SELECTING THE EXTERNAL DRIVE under Startup Disk in System Preferences. Note that the external drive volume *did show up* there. So under some conditions at least, the external volume is identified as a bootable volume. (This didn't work either, though: When I shut down the computer and booted up with the external drive connected, it still booted up from the internal drive.)
POSSIBLE EXPLANATION?
My external drive is partitioned into three partitions of different formats:
1. "Mac OS X Extended (Journaled)"
2. "Mac OS X Extended (Journaled)"
3. "MS-DOS File System (FAT32)"
The bootable volume is the first partition with the os x format.
Could my problem be caused by this partitioning of my external drive?
Either way, what to do?? I hope some of you savvy people out there can help me out.
Cheers,
Philip

Hi Philip,
My problem has been fixed, & I imagine it's the same for you...:
With the excellent help from Dave Nanian at shirtpocket.com - the developer of 'SuperDuper!' (thanks Dave - you rock!), the problem (as Michael suggested) is to do with the Partition Scheme of the drive.
If your drive was like my portable LaCie Porsche drive, it was FAT32-formatted for PC out of the box. This format has an underlying MBR (master boot record) partition-scheme. When re-partitioning a drive in 'Disk Utility', the original partition-scheme sticks, so if you simply re-partition the drive to Mac OS Extended, it will still have an MBR partition scheme... which Macs cannot boot from!
For a Power PC Mac to be able to boot from an external firewire drive, the drive MUST have an APM (Apple Partition Map) Partition Scheme underlying the Mac OS Extended partitions. To do this, click on the 'Options' button in 'Disk Utility' when on the 'Partition' page before partitioning. You will see the options:
GUID Partition Table (for Intel Macs... (n.b. Power PC's cannot boot from a GPT drive))
Apple Partition Map (to create a bootable drive for a Power PC Mac)
Master Boot Record (to create a bootable PC drive)
So.... to make your external drive bootable for your Powerbook G4, choose 'Apple Partition Map' in the 'Options' page prior to partitioning.
Special note about Intel Macs: Contrary to info supplied by Apple, an Intel Mac CAN boot from an APM-partitioned drive (this is why the OSX installer can be univerally bootable!), BUT, the problem is that the OSX installer will NOT let you install OSX-intel on an APM-partitioned drive....
You can, however, clone an Intel-Mac-OSX internal drive that has a GPT partition-scheme (using CCC or SuperDuper) to an external drive with APM, & the Intel Mac will still be able to boot from that clone...
The only real use for doing this, though, is if you want a multi-partitioned backup drive with separate bootable partitions for OSX-PPC & OSX-Intel machines. (Remember that a PPC machine cannot boot from a GTP-partion-scheme drive, hence the need to use APM in this instance seeing as the Partition Scheme applies to the entire drive (it can't be different for each partition.)
Good luck - let us know how you get on!
Jason

How do I install a bootable copy of Tiger to an external Firewire drive?

I've got a problem with my optical drive and cannot boot from a CD or DVD on my 17" flat panel iMac, running 10.2.8. I have bought Tiger and would like to upgrade my OS but want to be able to run some disc repair utilities on the iMac prior to doing the upgrade but can't run them on my boot disc.
I'd like to be able to install Tiger on my external FW hard drive, install Techtool pro on that same drive and then try to repair the internal drive on my iMac by booting from the external drive. Is that possible? Is it a good idea? Can I install to the external drive from my internal Superdrive without being able to boot from the install DVD? How should I do that?
Thanks in advance for any help.
Michael

Because you must boot from the Tiger DVD in order to install Tiger I'm afraid you are somewhat out of luck. However, with no guarantee either express or implied here's something you can try:
First, download a freeware utility called Carbon Copy Cloner from www.versiontracker.com or www.macupdate.com. Second, connect your Firewire drive and insert the Tiger DVD into the optical drive. Be sure it mounts on the Desktop along with the Firewire drive. Third, open your Disk Utility from the Utilities folder and use it to format or erase the Firewire drive. If you prefer you may wish to partition the Firewire drive to allocate a partition for the Tiger DVD (you will need about 6 GBs.) Fourth, open the CCC utility and click on the Lock icon beside the grayed out Clone button and authenticate. Then click on the Preferences icon. In the section labeled "Target Disk Options" be sure that the box labeled "Make bootable" is checked. No other items should be used. Click on the Save button. Fifth, select the Tiger DVD as the Source Disk, select the partition on the Firewire drive as the Target Disk. Now click on the Clone button.
Go away for a while because the clone process will take time. Once it finally completes you can eject the Tiger DVD. You now should be able to boot the computer from the Firewire drive partition. Open your Startup Disk preference pane, select the Tiger partition on the Firewire drive from the icon list, then click on the Restart button.
If this works your machine will boot into the Tiger installer from the Firewire drive. You can then install it onto your iMac. I would suggest you use the Archive and Install option. You may find the following helpful:
http://discussions.apple.com/thread.jspa?messageID=607363&#607363

60 GB external Firewire Drive Won't Mount

I have a 60GB external Firewire Drive that I have been using for a long time. I just turned on the computer and it won;t mount. I opened up the Disk Utility and I see that on the left side it says "57.3 GB Maxtor." I repaired permissions and verify disk. It still won't mount.
I don't want to have to erase it if possible. There are files I need on that drive. How can I get it to mount so I can grab some files off of it and move it to another drive?
Thanks in advance

Hi Edwurd,
What the message is telling you is that Disk Utility and the "underlying task," the Unix utility fsck, can't repair the volume.
Time for stronger medicine if the data is critical. There are commercial products that work differently and can recover disks when fsck can't. Look at Disk Warrior or Drive Genius. BUT... given that Disk Utility thinks it's a "non HFS volume," I wouldn't be optimistic.
If the external drive's data is unimportant - e.g., a backup you could rewrite - then see if Disk Utility can repartition and erase the drive. If only the catalog or partition map is bad, this will get you a working drive. But if you can't repartition with Disk Utility, suspect a hardware malfunction and check your warranty.
Good luck,
John

Installing on External Firewire Drive

Hi-
My Mac has started doing some funny things recently; I cant connect any USB devices, MobileMe refuses to let me delete any items from my iCal and other little irritations.
I have an external 4Tb Firewire Drive which has loads of space on it free, so I want to do a complete re-install of OS X and boot from from the external drive. I can then reinstall my apps and stuff bit by bit and see what is causing the problems.
The question is: when I install the system onto the FW drive, will it erase what is already on there? I have some important work on it and don’t want to lose it! Does the installer need a ‘clean’ disc to install?
Thanks, Andy

Disk utility's Restore function (and other copying apps such as CCC) will make a bootable installation of Snow Leopard on an external firewire drive that already contains data. Just remember not to check the erase disk option for the firewire drive.
It's most convenient if you first collect all your user material on the firewire drive into one folder. And there is possibly a risk of something bad happening if some files in your user material have names identical to the names of files in the Snow Leopard installation. That may be unlikely. But you'll have to judge that.
If that worries you, before you do the Snow Leopard installation on your firewire drive, you can use disk utility to repartition your external drive without erasing any of its data. See this: http://www.peachpit.com/articles/article.aspx?p=1395749. With such a large firewire drive, a number of partitions would seem desirable.
Then you can install a bootable Snow Leopard on an empty partition of the firewire drive for which you do check the erase disk option. With that option checked, the copy is performed as a block by block copy. Otherwise it's performed as a file by file copy. The block by block copy goes faster and is supposed to be identical in all respects to the original. That's not so with the file by file copy -- though both provide equal functionality.
Your firewire drive should be partitioned GUID. You can use APM (and the copy will still be bootable) but you will not be able (I've read) to install Snow Leopard updates. You can't, alas, change the partitioning scheme without erasing your firewire drive.
Message was edited by: Roy Vincent
Message was edited by: Roy Vincent

Installing Applications on external FireWire drive - a good idea?

Hello,
I'm planing in using a MacBook Pro with 128GB SSD. The idea is to install only essential stuff and store other things on an external FireWire 800-enabled HDD.
How big is the general difference in acces/transmission times compared to an internal generic HDD? And is the performace sufficient to even run applications from that external drive, should I run out of space on the SSD?
Will I spot a significant difference if I'm for example editing videos where all the files and the workspace are on that external drive while only Adobe Premiere is installed on the SSD?

Is the firewire drive new? Do you have any data on it? I am guessing the answers are Yes and No. If this is the case, the drive is probably formatted wrong for the Mac Pro. Depending on the manufacturer, the drive may be formated in FAT (for windows) or as Apple Partition Map. APM is for booting PowerPC (G3, G4, and G5 Macs). You have a Mac Pro and the drive needs to have a GUID partition. Drives without a GUID partition will not be recognized as valid targets in the installer.
If you follow the rest of this thread, and you have data on the firewire drive, it will be lost unless you back it up. That is your warning. To reformat the drive, do this:
1: Open /Applications/Utilities/Disk Utility
2: In the left column there will be a list of the drives and volumes available on the machine. The drive is listed first and the volume is indented beneath it. Select the Firewire drive, not its volume
3: On the right panel, select the Partition tab
4: Change the Volume Scheme setting from Current to One Partition
5: Give the new volume you are going to create a name
6: Press the Options button
7: There are three choices, GUID, APM, and MBR. Choose GUID since this is an Intel system. Press OK.
8: Press the Apply button - THIS WILL DELETE ALL DATA ON THE FIREWIRE DRIVE
Now reboot from the installation CD and perform the installation.
I will say however, that a drive with a boot OS on it is nice, but kind of useless. Isn't your data a little more important? Since you are not on Leopard, you might want to consider using ASR (the Restore tab in Disk Utility) to periodically clone your main volume to the backup volume. Then, not only do you have a bootable second drive but you also have all your data and personal settings. For extra credit go check out http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html
Hope this helps

Partitioning an external hard drive for Mac and PC

I want to partition an external hard drive (3TB) into 3 even partitions. I want to use one for PC storage, one for Mac storage and the last for Mac backup. Is this possible and how do I do it?

Drive Partition and Format
1. Open Disk Utility in your Utilities folder.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Apply button and wait until the process has completed.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
7. Re-partition the drive to create the three partitions. The one you wish to use on a PC you should format MSDOS (FAT).
When you connect the drive to your PC it should have no problem reading the partition set up for a PC. Now while on the PC you may wish to consider reformatting that partition using ExFAT (if supported on your PC.) This format is more compatible with both OS X and NTSF supporting long file names and other FAT filesystem irregularities.

Should I partition my external hard drive for FCPX media management?

Is there any benefit to creating partitions on a single external hard drive for media management purposes?
My thoughts were to divide a 1tb external firewire drive into 3x 300gb slices and leave 100gb as "free space".
Each partition would be dedicated to at least 1 active event + project (using FCPX terms) that I am editing.
My thinking on this is that when dealing with the source media + event database, OSX/FCPX will only work on the partition that has been improving read/write speed.
I could easily be wrong about this.

In my view there is no point in partition the drive. You are wasting space and speed. Events are segregated in the FCP folder structure. There is no need to to it with partitions.

How can I partition my external hard drive supporting mac OS in one partition and windows OS in another?

Hello everyone, how can I partition my external hard drive supporting mac OS in one partition and windows OS in another?

OK. Start with:
1. Open Disk Utility in your Utilities folder.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to two (2). Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
4. Click on the Erase tab in DU's main window. Select one of the two partitions, preferably the first one, change the Format type: to MSDOS then click on the Erase button.

Trouble with installing 10.5 from an external firewire drive

I have a family pack of 10.5 and installed it just fine on my macbook. But, I'm having trouble getting my imac DVD player to read the DVD. It just spins and spits it out, and spins and spits it out. The imac is not covered under applecare so spending money to get the DVD drive fixed (which I barely use) is not something I want to do right now.
Anyway, I followed instructions on a this website to install 10.5 from an external firewire drive. (http://iuseapple.com/blog/apple-how-to/advanced-os-x/2007/10/29/how-to-install-l eopard-from-external-firewire-hard-drive/)
But I get stuck and am not able to actually get my imac to boot from the installer. Basically, I am able to use disk utility to create a copy of the disk image on my macbook. That resulting file ends in ".cdr" and it mounts when I double click it.
And I partitioned my firewire hard drive without problems.
I think I'm messing up when it comes to doing the restore. If I try to drag the .dmg mounted file in to the "source" it doesn't work (is greyed out). If I try to drag the mounted .dmg there than it works, but I get an error when I click "restore" (something about scans and images not being found). I tried physically copying the .dmg file onto the partition, but then when I plugged the HD into my imac, I wasn't able to get the imac to boot from the installer.
What am I doing wrong? If someone could walk me through these last steps I'd appreciate it!

Okay I finally got around to creating the bootable disk image of 10.5 using Carbon Copy Cloner. Still my iMac is not booting from the firewire drive!
Here's a recap of everything I've tried. I'm at a complete loss now!
- I partitioned the HD into 2 partitions-- a 10gig one for the 10.5 install, the then the rest for Time Machine. I make the partition in Disk Utility on my MacBook.
- I've partitioned the drive a few times-- always partitioning it in APM format (b/c it needs to boot my non-intel iMac).
- I've created the disk image using "restore" in disk utility. I've again tried this a few times.
- I am able to boot my MacBook from the disk image I create! So I know the FW drive is able to be used to boot from!
- Here's what I've tried in terms of getting the iMac to boot from the FW drive. It always just boots to my internal drive instead. Sometimes I briefly see a folder and question mark. I've tried all 3 FW ports. I've selected the install partition at start up in preferences. I've also held down the option key at start up (only my internal drive shows) and I've held down command-option-shift-delete and again I get the question mark and it boots to my internal drive.
- And I installed Carbon Copy Cloner and made the disk image that way on my macbook. Still, I tried everything and the iMac is not able to boot from the firewire drive!
Since my DVD drive is broken, this is the only way for me to install 10.5! Help!

Partition of External Hard Drive

I am trying to partition an external hard drive into three partitions - one for the time machine backups, one for miscellaneous storage and one for storage of files that I can share with a PC. I was able to partition the drive successfully but all three partitions are in the Mac OS Extended (journaled) format. I understand that I need to change the format of the part I want to share with the PC into FAT but when I click on that drive, I don't have the option. I tried looking under the "erase" tab but the only options are: Mac OS Extended (journaled); Mac OS Extended; Mac OS Extended (case sensitive journaled) and Mac OS Extended (case sensitive). Now, if I look at the entire hard drive (not clicking on one of the partitions), the option is there. I could erase the entire thing using the MS DOS (FAT) option, but I don't want to do that. How can I format only one of the partitions in the MS DOS (FAT) format?

I think it's because of the drive's Partition Map Scheme. In Disk Utility, select the drive in the left side bar. Look at the bottom of the window, and find Partition Map Scheme. If it is Apple Partition Map, you will not be able to format it as MS-DOS (FAT).
The way to fix this is to go to the Partition tab. For Volume Scheme, select 3 Partitions (even if it already is 3 partitions). Click on the Options... button. In the window that opens, select either GUID Partition Table or Master Boot Record. GUID Partition Table would be best for use on the Mac, as long as the PC is OK with it (I'm not sure). Now, when you return to the Partition tab, you should be able to select MS-DOS (FAT) for one partition while keeping the others formatted for Mac.

Can WinXP be loaded and booted from external firewire drive?

The subject line probably says it all but:
Does the recent firmware upgrade and/or BootCamp allow you to install WinXP on an external Firewire drive rather than partitioning the iMac Core Duo's internal drive?
Mike
Intel iMac Mac OS X (10.4.6)

The other problem is XP itself doesn't support booting from firewire. Even if someone could figure out how to install to an external from bootcamp, you would still have to contend with XP.
Glor

Lion mysteriously erases SSD partition on external FireWire drive.

Similar Messages

Maybe you are looking for