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Q: Repairing Boot Camp after creating new partition

I'm running OS X 10.8 and Windows 7 x64 Pro.

 

After properly setting up Boot Camp to dual-boot Windows on my Mac mini, I decided to test whether or not it was true that creating another partition (a data partition for OS X) would interfere with Boot Camp.  Wikipedia claims it does interfere but without citing a source, whilst the Boot Camp documentation itself only specifies that the disk must be a single partition _prior_ to setup - there's no mention of whether the disk must be _kept_ that way afterwards.

 

I opened Disk Utility, reduced the size of my OS X parition from 420GB to 80GB, and created a new partition in the unallocated space.  Here's how it looks now:

/___sbsstatic___/migration-images/190/19047693-1.png

When I attempted to proceed with the process, I did receive a warning that doing this (and I quote), "may" cause problems with Boot Camp.  Seeing as it was inconclusive, I thought I'd give it a shot - nothing ventured…

 

Of course, it borked Boot Camp, otherwise I wouldn't be posting here.  Whilst OS X boots just fine, the Boot Camp partition now no longer shows up in the Startup Manager, though it does in the Startup Disk prefPane.  If I do attempt to boot into Boot Camp, I receive the following message on a black screen:

No bootable device --- insert boot disk and press any key

The advice given to someone who had this same problem was, "fix your damaged Boot Camp volume."  But I'm at a loss as to how to do that.

 

So, anyone know how to proceed now so that I can keep my partitions as is, whilst fully restoring normal Boot Camp functionality?

Mac mini (Mid 2011), Mac OS X (10.7.4)

Posted on Jul 26, 2012 11:28 PM

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Q: Repairing Boot Camp after creating new partition

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  • by C_Jones,

    C_Jones C_Jones Sep 18, 2012 10:06 AM in response to Christopher Murphy
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    Sep 18, 2012 10:06 AM in response to Christopher Murphy

    Christopher,

     

    Thank you very much for your response, I really appreciate your input on this. You are like the man on this boot, mbr items. I actually have to work in windows or my job and mac for other things so I need windows 7 and mac osx. When adding a SSD drive I freed up room on my prumary HD.  So I got a little nutty and thought it would be nice to have a win8 installation to start working with as well (for work), and also it would be nice to have a partition "drive" that all three operating systems could access to share files. hence the "STORAGE" drive in ms-dos format.  then there are the system created partitions so yes it does end up being 5 partitions. I know it is a bit extreme but I would have liked to have it work, but it looks like I just need to drop the win8 and storage drive and have that space reclaimed by osx. So thats the why, is there any hope?  if not would it be difficult to remove the bootcamp8 and storage partitions and have that reclaimed by osx?

     

    thanks again.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 10:43 AM in response to jupe699
    Level 3 (555 points)
    Sep 18, 2012 10:43 AM in response to jupe699

    @jupe699

    So the problem your'e having is booting from the Window DVD? Have you tried burning a DVD-R instead of DVD+R? There's a big difference between the two. Another thing to consider is making a USB boot stick if you have a new enough model Mac that Boot Camp Assistant presents you with the option to make USB bootable media.

  • by jupe699,

    jupe699 jupe699 Sep 18, 2012 10:45 AM in response to Christopher Murphy
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    Sep 18, 2012 10:45 AM in response to Christopher Murphy

    I don't know if the problem is due to the fact that i try to install windows from an external dvd. The external one works fine though in OS X. Tried all types of discs. Also tried with the usb stick and i still get the same message. No bootable device.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 10:50 AM in response to C_Jones
    Level 3 (555 points)
    Sep 18, 2012 10:50 AM in response to C_Jones

    @C_Jones

     

    The problem is that the instant you go off the rails that Apple has provided, you have to know a lot of crazy details about MBR, GPT, various ways to make "valid" hybrid MBRs (in that none are truly valid or standard) as well as how EFI and CSM (legacy BIOS) behave. Bootloading is complicated with lots of interaction between the various details. Apple makes it far less complicated via restrictions. By rejecting just one of their restrictions, you've opened about 90 cans of worms.

     

    So presumably you're referring to disk1 which has 5 partitions, two of which are Windows, and what you want to do is blow away the two Windows partitions and reclaim the space for Mac OS X. Is that correct?

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 10:58 AM in response to jupe699
    Level 3 (555 points)
    Sep 18, 2012 10:58 AM in response to jupe699

    @jupe699

    Apple's computers have limited support for booting Windows from external sources. The boot camp guide is clear about the external dvd player needing "compatible external optical drive" and "For information on using your computer with an external optical drive, see the documentation that came with your computer. "

  • by jupe699,

    jupe699 jupe699 Sep 18, 2012 11:01 AM in response to Christopher Murphy
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    Sep 18, 2012 11:01 AM in response to Christopher Murphy

    Thanks, so i take it everything looks good on my partitions and stuff. I just have somehow to replace my superdrive then. I just wanted to make sure that's the issue so that i don't replace it and still not working. Also the usb stick not booting up made me suspicious and i thought it might have something to do with the disk.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 11:21 AM in response to jupe699
    Level 3 (555 points)
    Sep 18, 2012 11:21 AM in response to jupe699

    I'm not familiar with the various models of Apple computers that support booting via USB sticks or external drives. So you could get a new external drive and still not be able to boot. Some models only boot from an internal optical drive. My Macbook Pro 4,1 from 2008 is one such computer.

     

    The partitions look reasonable.

     

    If you have previously had Windows installed on this internal disk (no externals connected), you could try zeroing the internal disk MBR bootloader area with the following command. You have to make sure you get the entire command on a single line before you hit enter, if you truncate the limiting commands at the end it will absolutely proceed to zero your entire harddrive without asking you for additional permission:

     

    sudo dd if=/dev/zero of=/dev/rdisk0 bs=440 count=1

  • by jupe699,

    jupe699 jupe699 Sep 18, 2012 11:25 AM in response to Christopher Murphy
    Level 1 (0 points)
    Sep 18, 2012 11:25 AM in response to Christopher Murphy

    Great, two last questtions.

     

    is this safe to do? Will i lose any data?

    and secondly, i tried to get into the recovery. I saw there that disk utility doesn't see the hidden recovery partition. It showed before i split it with boot camp, that my only partition was 935GB (the rest was for the recovery, although i couldn't see it). So my second question is, if i reformat it from there, i will lose the ability to proceed with the recovery i guess, right?

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 11:32 AM in response to jupe699
    Level 3 (555 points)
    Sep 18, 2012 11:32 AM in response to jupe699

    If you get the command correct, with the 440 byte block size and single count limiter, it will only zero 440 bytes of data on the drive, which is the bootloader code region of the MBR. If you get it wrong, yes you'll lose a lot of data. If you don't have good backups, then you're taking a HUGE risk just by using a computer, let alone higher risk activities like using Boot Camp Assistant and Windows on your computer.

     

    Recovery HD has a partition type GUID for Apple Boot, rather than Mac OS X Extended. So Disk Utility and the Finder always hide it and do not mount it by default. I don't understand your question: if you reformat what? Proceed with what recovery? What does Recovery HD have to do with anything you've brought up so far?

  • by jupe699,

    jupe699 jupe699 Sep 18, 2012 11:46 AM in response to Christopher Murphy
    Level 1 (0 points)
    Sep 18, 2012 11:46 AM in response to Christopher Murphy

    i was thinking if none of it works, maybe try to do it like when i had Snow Leopard, where the disk was 1 partition only, without any secret partitions (recovery). So i was thinking to go into recovery, reformat it as 1TB (instead of 935GB) that can see it now and proceed from there. I just don't know if it will work and download OS X from the internet or it will break.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 12:00 PM in response to jupe699
    Level 3 (555 points)
    Sep 18, 2012 12:00 PM in response to jupe699

    If you boot from Recovery HD, and repartition with 1 partition in the GUI, in reality you will have two partitions because the EFI System partition is a requirement GPT disks as this is part of the (U)EFI spec. After you download and reinstall Lion or Mountain Lion, you will have three partitions. There is no way around this.

     

    Even with Snow Leopard a single partition disk in the GUI really had two partitions, because the EFI System partition is a requirement for GPT disks.

     

    After installation, you can manually delete the Recovery HD partition. But in so doing you lose the ability to boot from a known good volume to do repairs on your primary volume, to do restores over the internet, and the ability to use File Vault 2. If you're willing to live with such limitations then you can delete the Recovery HD partition using something like gdisk, before you resize the disk with Boot Camp assistant. But I don't know what the point of doing this would be.

  • by jupe699,

    jupe699 jupe699 Sep 18, 2012 12:02 PM in response to Christopher Murphy
    Level 1 (0 points)
    Sep 18, 2012 12:02 PM in response to Christopher Murphy

    Thanks a lot for your answers!

  • by C_Jones,

    C_Jones C_Jones Sep 18, 2012 4:31 PM in response to Christopher Murphy
    Level 1 (0 points)
    Sep 18, 2012 4:31 PM in response to Christopher Murphy

    Hi Christopher,

     

    yes disk 1, is it possible to go back to just the mac osx installation and the recovery hd on that drive and have the two windows go away and then have the mac osx drive and the windows drive disk0 play nice with bootcamp and start up?

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Sep 18, 2012 4:48 PM in response to C_Jones
    Level 3 (555 points)
    Sep 18, 2012 4:48 PM in response to C_Jones

    Make sure you have backups for Mac OS data, and then remove the two partitions with Disk Utility. In Disk Utility click on the drive icon (not volume icons, the one with the drive model #), then on the Partition tab, then on the partition you want deleted, then click the - button (the minus button) below the partition diagram. Do this again for the second partition you want deleted. Reboot.

     

    Then go to Terminal and type:

     

    diskutil resizevolume /dev/disk0s2 limits

  • by C_Jones,

    C_Jones C_Jones Sep 19, 2012 8:03 AM in response to Christopher Murphy
    Level 1 (0 points)
    Sep 19, 2012 8:03 AM in response to Christopher Murphy

    I will try this evening and let you know how it goes.  Thanks.

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