Boot camp partition not recognized.

Discussion in 'Windows, Linux & Others on the Mac' started by Apollo33, Aug 14, 2009.

  1. Apollo33 macrumors regular

    Joined:
    Jun 26, 2007
    #1
    After letting Windows 7 install (with empty, unpartitioned space) it created a 100MB recovery partition (WinRE) which seemed okay. But I can't mount the NTFS partition in OS X now. It fails to recognize it. It sees the unrecognizable WinRE partition and seems to not look any further (that's my guess, at least).

    Picture attached from Disk Utility of the space that SHOULD contain TWO separate partitions. One for WinRE, the other an NTFS partition for Windows 7.

    I guess I could delete the WinRE partition, but doesn't that defeat the purpose of having a recovery partition?
     

    Attached Files:

  2. Stridder44 macrumors 68040

    Stridder44

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    #2
    That is very strange. You should see your OS X partition and the Windows partition (I've never seen the 100 MB space ever show up under Disk Utility).

    Have you done anything in 7 yet or just simply installed so far? If not, I'd say delete the Windows partition and start over from scratch.
     
  3. badger-w macrumors newbie

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    Aug 13, 2009
    Location:
    Midlands, UK
    #3
    In the picture the selected partition is a lot bigger than 100MB, it shows as 165.4GB, FAT32 - is that Windows 7 or WinRE?

    Also do you have NTFS drivers installed in OS X?
     
  4. Stridder44 macrumors 68040

    Stridder44

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    #4

    You shouldn't need to install drivers. OS X can already read (but not write) NTFS.


    EDIT: Apollo33, there's no way you could have installed Windows 7 yet. It shows the drive being formatted as FAT32. Vista and 7 require NTFS and won't install on FAT32. Delete the Windows partition and start over. Once the Windows 7 installer has brought you to the hard drive screen, select the partition labeled BOOT CAMP (it'll be in caps). Click the "drive options" button on the lower right and then click "format". It'll look something like this (not my image, just an example):

    [​IMG]
     
  5. Apollo33 thread starter macrumors regular

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    Jun 26, 2007
    #5

    Uhm. I've been a Windows user for as long as I can remember. I think I would know if I'd installed Windows or not.

    I can, in fact, boot into Windows 7 by holding the Alt key at start-up. However, Start-up Disk in the OS X system preferences doesn't show the Windows partition either.

    And there's no 100 MB partition in Disk Utility. The 100 MB partition is only seen by Windows 7 (it created it to hold WinRE... Windows 7's disk management refers to the filesystem for it as "System").

    All of this leads me to believe that OS X isn't recognizing the 100 MB partition that Windows created, and is thus trying to read the entire space (both the System partition and the NTFS partition).

    In addition, Disk Utility simply labels it as FAT32 because it has no clue what type of file system it is. If I try to mount the partition manually through the Terminal, it says:
    mount: /dev/disk0s3: unknown special file or file system.

    It's certainly not FAT32 and there IS data there, as I can boot into Windows 7 just fine.

    So no one else has had this issue with Windows 7 installing WinRE?
     
  6. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #6
    Can you show us the results of 'fdisk /dev/disk0' and 'diskutil list' please?

    http://developer.apple.com/documentation/Darwin/Reference/ManPages/man8/fdisk.8.html
    http://developer.apple.com/documentation/Darwin/Reference/ManPages/man8/diskutil.8.html
     
  7. Apollo33 thread starter macrumors regular

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    #7

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  8. Stridder44 macrumors 68040

    Stridder44

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    #8

    You sure about that? Because Disk Utility shows something a little different for me.

    [​IMG]

    Notice how at the bottom it says Windows NT File System (NTFS). Honestly I'm not calling you a liar, I believe what you say. But there's something seriously wrong here because Windows 7 REQUIRES NTFS. I mean it will absolutely not install on FAT32.
     
  9. Apollo33 thread starter macrumors regular

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    Jun 26, 2007
    #9
    I said it's not FAT32 already. It's two distinct partitions as shown by FDISK. Notice how rows 3 and 4 denote "HPFS/QNX/AUX"? Row 3 is the System partition that Windows 7 created for WinRE. It's 100MB. Row 4 is the NTFS partition where Windows 7 is installed.

    I know this for a fact because that's exactly what it says when I load Disk Management in Windows. Perhaps I should screenshot that.
     
  10. Stridder44 macrumors 68040

    Stridder44

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    #10
    Please, do.
     
  11. Infrared macrumors 68000

    Infrared

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    Mar 28, 2007
    #11
    Ok. I can see what has happened now. As you may know, your
    drive has two partition tables. A GUID partition table and an MBR
    partition table. It's a hybrid scheme.

    When you use Disk Utility to add a FAT partition, say, it alters both
    partition tables.

    But the Windows installer has only altered the MBR partition table.
    The two tables are not, therefore, consistent.

    There is a utility 'gptsync' for achieving consistency, but it works
    in the wrong direction: that is, it brings the MBR partition table into
    line with the GPT. You would want to go the other way.

    I don't know if you will find this informative or helpful in any way:

    http://www.mydigitallife.info/2009/...m-been-created-during-windows-7-installation/

    It might just be possible to get things consistent with 'gpt':

    http://developer.apple.com/documentation/Darwin/Reference/Manpages/man8/gpt.8.html

    That command is dangerous. Only proceed with extreme caution.
     
  12. EOC macrumors newbie

    Joined:
    Aug 14, 2009
    #12
    I'm having a similar problem in that I'm not able to see my Windows partition or my ntfs storage partition in osx on my 13" mbp. I've tried the Paragon NTFS and NTFS 3g programs but I've discovered that the partitions aren't mounting at all. I've tried two installs of Vista and I'm currently using Win7 rc1 but all 3 times the partitions don't mount in osx. Any ideas why this isn't happening?

    I have a 40 gb windows partition(ntfs), 400gb storage partition(ntfs) and a 30gb osx partition.
     
  13. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #13
    I could only speculate as I don't know the sequence of events that led
    up to that. But, as a general rule, it is best to create your partitions in
    Disk Utility in advance.
     
  14. EOC macrumors newbie

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    Aug 14, 2009
    #14
    Okay, I'll give that a try. I think I did make both partitions during the windows setup process. Thanks.
     
  15. Stridder44 macrumors 68040

    Stridder44

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    #15
    Awesome info!
     
  16. badger-w macrumors newbie

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    Midlands, UK
    #16
    I had exactly the same issue after creating an NTFS partition from within Windows, I can confirm that the gpt command is what you'll need. Good news is that it won't erase the partition, so it saves some time later on if you've got stuff on it.

    Like Infrared said, the command can be dangerous so take care when using it, and as always make sure anything important is backed up! ;)
     
  17. Apollo33 thread starter macrumors regular

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    Jun 26, 2007
    #17
    I tried looking into gpt, but couldn't figure it out. I think what I'll do is I'll create TWO NTFS partitions in Disk Utility (one 100MB and one for the rest) and then let Windows 7 install the recovery partition as it desires.

    EDIT: Eh. DiskUtility can't create partitions smaller than 1.07 GB. I guess I'll just let it partition the entire thing as a single NTFS partition and then install without WinRE.
     
  18. Apollo33 thread starter macrumors regular

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    Jun 26, 2007
    #18
    So how'd you do it? I'd like to avoid re-installing Windows 7 if possible.
     
  19. badger-w macrumors newbie

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    Midlands, UK
    #19
    Boot Leopard from an external hard drive - I had already used Carbon Copy Cloner to back up my Mac and so was able to use that. You may also be able to do it from the Leopard install DVD as I think that gives you a terminal too.

    You'll also need rEFIt's partition inspector, simplest way is to download and install rEFIt and it'll be in Applications/Utilities

    Assuming your internal disk is disk0 you can do the following:

    Dismount the drive:
    Code:
    sudo diskutil unmountDisk disk0
    Check out its partition tables, now I can't remember whether it was rEFIt's Partition Inspector or gpt that showed me partitions that existed in the MBR but not the GPT, so try both.

    With rEFIt:
    Applications > Utilities > Partition Inspector

    With gpt:
    Code:
    sudo gpt show disk0
    Note that rEFIt shows you (in sectors) the starts and ends of your partitions, whereas gpt shows you the offsets and sizes. Save outputs of both programs because you will need to know this information.

    One of the above methods will show you the MBR-only partition that Windows created. If not, delete the entries from your GPT table and try again. If your MBR is correct then you may want to remove all the GPT entries anyway and recreate them according to the MBR, much like gptsync in reverse.

    Code:
    sudo gpt remove -i 1 disk0
    sudo gpt remove -i 2 disk0
    sudo gpt remove -i 3 disk0
    [...]
    The -i option refers to the index in the GPT and may be different for you. The output from gpt show will tell you the indexes.

    It seemed that every time I used the gpt command the (recognizable) volumes on the drive kept being remounted, which was a real pain. I ended up just pasting the unomunt command from the clipboard every time I used gpt.

    Finally to recreate the GPT:

    Code:
    sudo gpt add -b 40 -i 1 -s 409600 -t efi disk0
    sudo gpt add -b 409640 -i 2 -s 125829120 -t windows disk0
    [...]
    Replace the sector offsets for your own according to your MBR.

    The man page for gpt details the options but in short:
    -b is where the volume starts
    -i is its index
    -s is its size
    -t is its type

    That's pretty much all you will need. If you have copied from your MBR then there's no need for gptsync, and you should be immediately able to read the drives.

    I know you're hoping to not have to format your drives but just for future reference - I've had trouble formatting NTFS volumes from Leopard's Disk Utility which I think is due to a permissions problem. Doing it from the command line with sudo solved this:
    Code:
    sudo diskutil eraseVolume "NTFS-3G" "Windows" disk0s2
    Hope that helps, if in doubt post the results from Partition Inspector
     
  20. supercooled macrumors 6502a

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    Sep 6, 2007
    #20
    The last few attempts of installing Windows on my Mac Pro have been a complete and utter nightmare. Everyt ime I initiate an install via Bootcamp in Leopard, I always lose the ability to boot back to OSX. Within Windows environment, I do not see OSX listed under "advanced settings" where you pick the boot sequence. OSX simply does not register. And holding Options upon boot simply stays in a perpetual black screen where if you press the power button it will hastily shut off rather than having to hold it til it shuts off (a difference I think).

    Is my machine cursed? I would love to have XP so I can run a few games un- compromised.

    I loathe to think of trying again but I really want to play rFactor and some other games but damnit, it's such a pain in the butt to rescue my Leopard from the ashes.
     
  21. badger-w macrumors newbie

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    Midlands, UK
    #21
    How are you creating your partitions? Are you letting Boot Camp split your OS X volume and then formatting it during Windows install or are you partitioning the drive itself during Windows setup?

    Generally you shouldn't change your partition structure from within XP - as in my last post it can be corrected but it's not pretty
     
  22. Infrared macrumors 68000

    Infrared

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    Mar 28, 2007
    #22
    If you have an available drive bay, I'd recommend using a separate
    drive for Windows. It avoids most of the problems discussed in this
    thread.
     
  23. Gav Mack macrumors 68020

    Gav Mack

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    #23
    The OP isn't a liar or insane because after installing 7 Ultimate RTM last night I have exactly the same issue with Disk Utility seeing only a FAT32 drive. I'll post back with the results when I get time to work on it later..
     
  24. Infrared macrumors 68000

    Infrared

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    Mar 28, 2007
    #24
    These issues are likely occurring because the Windows 7 installer
    will create two parititions if it can (certain conditions need to be
    satisfied before it will do this).

    The extra partition is for:

    (1) A Windows recovery environment.
    (2) BitLocker support.
    (3) EFI native booting.
    (4) Flexible OS switching.
    (5) Anything else I can't think of.
     
  25. Gav Mack macrumors 68020

    Gav Mack

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    #25
    It's for (1). It's my fault for cutting corners not using boot camp in OSX to remove and recreate the bootcamp volume. I simply erased the partitions that 7 RC created and letting 7 RTM setup recreate them, but because RTM uses a 100Mb RE instead of 200Mb for 7 Beta and RC (which worked fine using this method before) so this time the GPT has lost sync with the MBR.

    What probably hasn't additionally helped I've also been tinkering with the partition trying to enable Nvidia AHCI support on 7 RC like users on the OSX86 forum have done with the Mac Pro :rolleyes:
     

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