4 Replies Latest reply: May 19, 2008 7:57 AM by bourne4
bourne4 Level 1 Level 1 (0 points)
After the release of the last Macbook Pro Firmware Update, I realized I do not have a GUID partition scheme. Rather than reinstalling Leopard and starting from scratch, I decided to use the Windows Disk Manager to change the disk from Basic to Dynamic. After doing so, I allowed it to reboot and held down the option key, only Windows shows up as a valid bootable option. All the partitions are there, my OSX partition is just fine, it is just not showing up. By changing it from Basic to Dynamic, it must have disregarded the MBR, or removed it completely. Honestly I am not to sure how a dynamic disk handles boot options. Does anyone have any ideas as to make OSX a bootable option again? Do I need to find a different bootloader? Right now I can only boot into XP, but my OSX partition is very much there (as of Disk Management). Any thoughts? (Reinstallation is not a very plausible option at this point)

Macbook Pro 15'', Mac OS X (10.5.2), Dual Booted with XP SP2
  • nerowolfe Level 6 Level 6 (13,070 points)
    bourne4 wrote:
    After the release of the last Macbook Pro Firmware Update, I realized I do not have a GUID partition scheme. Rather than reinstalling Leopard and starting from scratch, I decided to use the Windows Disk Manager to change the disk from Basic to Dynamic. After doing so, I allowed it to reboot and held down the option key, only Windows shows up as a valid bootable option. All the partitions are there, my OSX partition is just fine, it is just not showing up.


    Welcome to the Apple forums:
    I don't think you can or should use Windows tools to modify an OS-X partition scheme.
    You must use the Leopard DU to do this, and you cannot change a partition scheme without erasing the HD, which means it has to be backed up.
    I thought all Intel boxes shipped with the GUID format.
    You need to backup everything and reformat your HD properly and then reinstall everything.


    By changing it from Basic to Dynamic, it must have disregarded the MBR, or removed it completely. Honestly I am not to sure how a dynamic disk handles boot options. Does anyone have any ideas as to make OSX a bootable option again? Do I need to find a different bootloader? Right now I can only boot into XP, but my OSX partition is very much there (as of Disk Management). Any thoughts? (Reinstallation is not a very plausible option at this point)


    Reinstallation may not be plausible, but it may be necessary.
    If you have a TM backup, it's a snap, assuming you did nothing to the partition scheme.
    Can you undo what changes you made?
    Again, without a backup, anything you do may cause data loss.

    From the Petri page regarding Dynamic Disks:
    Dynamic storage is supported in Windows XP Professional, Windows 2000 and Windows Server 2003. A disk initialized for dynamic storage is called a dynamic disk. A dynamic disk contains dynamic volumes, such as simple volumes, spanned volumes, striped volumes, mirrored volumes, and RAID-5 volumes. With dynamic storage, you can perform disk and volume management without the need to restart Windows.

    Note: Dynamic disks are not supported on portable computers or on Windows XP Home Edition-based computers.
    You cannot create mirrored volumes or RAID-5 volumes on Windows XP Home Edition, Windows XP Professional, or Windows XP 64-Bit Edition-based computers. However, you can use a Windows XP Professional-based computer to create a mirrored or RAID-5 volume on remote computers that are running Windows 2000 Server, Windows 2000 Advanced Server, or Windows 2000 Datacenter Server, or the Standard, Enterprise and Data Center versions of Windows Server 2003.
    Storage types are separate from the file system type. A basic or dynamic disk can contain any combination of FAT16, FAT32, or NTFS partitions or volumes.
    A disk system can contain any combination of storage types. However, all volumes on the same disk must use the same storage type.

    Link:
    http://www.petri.co.il/differencebetween_basic_and_dynamic_disks_in_windows_xp_20002003.htm

    Message was edited by: nerowolfe
  • bourne4 Level 1 Level 1 (0 points)
    {quote:title=nerowolfe wrote:}I thought all Intel boxes shipped with the GUID format.

    {quote}
    I have formatted and reinstalled several times, but have never paid notice to the GUID partition option...

    {quote:title=nerowolfe wrote:}
    Reinstallation may not be plausible, but it may be necessary.
    If you have a TM backup, it's a snap, assuming you did nothing to the partition scheme.
    Can you undo what changes you made?
    Again, without a backup, anything you do may cause data loss.{quote}


    I do not have a time machine backup, it would be great if you can do a time machine backup over a network. But I do have a backup I made about a month ago, but there are still a lot of files that have been modified since then. I cannot undo the changes, once you convert to a dynamic disk, you cannot convert back. My OSX partition is still there, so I my data should be alright. I can just use a Live Linux CD and get all my data off if it has to come to that. My hope is that since the OSX bootloader is still present, that I might just be able to make a few changes and active my OSX partition. It might have just been mapped weird at the conversion. Thanks for the reply!
  • nerowolfe Level 6 Level 6 (13,070 points)
    bourne4 wrote:
    {quote:title=nerowolfe wrote:}I thought all Intel boxes shipped with the GUID format.

    {quote}
    I have formatted and reinstalled several times, but have never paid notice to the GUID partition option...

    {quote:title=nerowolfe wrote:}
    Reinstallation may not be plausible, but it may be necessary.
    If you have a TM backup, it's a snap, assuming you did nothing to the partition scheme.
    Can you undo what changes you made?
    Again, without a backup, anything you do may cause data loss.{quote}


    I do not have a time machine backup, it would be great if you can do a time machine backup over a network. But I do have a backup I made about a month ago, but there are still a lot of files that have been modified since then. I cannot undo the changes, once you convert to a dynamic disk, you cannot convert back. My OSX partition is still there, so I my data should be alright. I can just use a Live Linux CD and get all my data off if it has to come to that. My hope is that since the OSX bootloader is still present, that I might just be able to make a few changes and active my OSX partition. It might have just been mapped weird at the conversion. Thanks for the reply!


    Good idea, try Ubuntu Linux. Others have used it and saved their OS 100%.
    You may have accidentally used the APS rather than the GUID during one of your formats, although I thought on an Intel box that GUID would be the default.
    Once you have your OS-X backed up you should be able to use it to regenerate itself on your HD once you fix it.
    I just hope the data are still in the proper format for OS-X to read it back.
    You might also look into "blessing" your current HD OS-X and you might be able to make it bootable again. You can google "blessing" for information. It's a process to make a "dead" OS bootable again.
    On some clone SW, SuperDuper, maybe, you will see the last step as "blessing" to create the bootable clone.
    Keep us posted.
  • bourne4 Level 1 Level 1 (0 points)
    Update on blessing...I booted from the OSX install cd and opened up terminal (also diskutil but all options are greyed out) and do a little research on the bless command. I looked in the /Volumes folder and the only volume that was mounted was my OSX CD, and when I check to see what is mounted ("mount"), my HD was not mounted. I try to mount my partition "mount /dev/disk0s1" and of course it fails to recognize the format and does not mount. What I am getting at is that I cannot issue the bless command due to there not being a volume to bless. Unless I can install bless on a linux distro, then that doesn't seem to work, unless I am doing something wrong.

    So I did give up on the option of fixing the MBR, or whatever was there. I decided to use this time to buy a 250gb hard drive and install it. So now I have my mac up and running on the 250gb, but I have a problem accessing my files on my old hard drive, the one with the messed up MBR. I can access it via Ubuntu through a SATA to USB adapter. When I click on my Mac partition, and go to "MacHD/Users/Myusername" it says that all the files are locked due to permissions. Oh how sneaky Apple, thanks for that one. So I issue the chmod command to try to change the permissions, but learn that the files are read-only. That's even better. So now I am downloading a Unix platform to see if I can access my files, since Mac is based off Unix. Does anyone have any other suggestions as to access my files and back them up? I appreciate the replies!

    Message was edited by: bourne4