3 replies to this topic

[tpho2500]

So I'm currently dual booting Snow Leopard (###### & ######) and Windows 7. I have an external monitor that I use whenever I'm at my desktop. I went to use my laptop in my living room and unplugged the monitor. When I booted up into Windows 7, I got a weird error message saying there was a hardware configuration change "Insert Windows 7 DVD and Click Repair". I guess I forgot to turn off "Extend Displays" before I unplugged it.

I inserted the Windows 7 DVD and "Repaired" Startup. I booted into Windows 7 successfully BUT my entire hard drive is now MBR and NOT GPT! Because MBR does not support more than 4 partitions, some of my partitions have been deleted OR moved.

When I launch gdisk in Windows and "print Partition table", I can see the missing partitions. Is there anything I can do to revert everything back? I don't have an external drive large enough to back up all of my data. I uploaded my important documents onto SkyDrive, DropBox, and Ubuntu One, but there's still a lot I'd like to keep.

Any help is appreciated!

Thanks,

tpho2500

[dmazar]

Snow leo and Win on the same drive? If yes, then you probably have hybrid disk and not pure GPT. That's the common case. Win always see this disk as MBR and OS X as GPT. You can install Win 7 to pure GPT disk only in UEFI mode and that is not the case here, right? I guess that when you boot to Snow Leo you will see all your partitions.

[tpho2500]

dmazar, on 24 July 2012 - 07:54 PM, said:

Snow leo and Win on the same drive? If yes, then you probably have hybrid disk and not pure GPT. That's the common case. Win always see this disk as MBR and OS X as GPT. You can install Win 7 to pure GPT disk only in UEFI mode and that is not the case here, right? I guess that when you boot to Snow Leo you will see all your partitions.

Yes, Snow and Win are on the same drive. Did the Windows "Start Up Repair" function turn it into a hybrid disk?

I can currently boot into both Windows and Snow Leopard, but I cannot "see" the "missing partitions".

Before this catastrophe, I could Read/Write to my HFS+ partitions using MacDrive. If I created a partition on Snow Leopard, Windows could see it and write to it. No problem.

Now when I boot into Snow Leopard, I cannot change my hard drive layout at all in Disk Utilities. SL sees the hard drive as "MBR". Is there anyway I can reverse all of this?

gdisk (for Windows) sees the missing partitions, however "Disk Management" sees it all as "Unallocated".

[dmazar]

tpho2500, on 24 July 2012 - 08:27 PM, said:

Yes, Snow and Win are on the same drive. Did the Windows "Start Up Repair" function turn it into a hybrid disk?

OS X made it hybrid when you created partition for Win on a GPT disk previously. Otherwise, you would not be able to install Win 7 without UEFI.

tpho2500, on 24 July 2012 - 08:27 PM, said:

Before this catastrophe, I could Read/Write to my HFS+ partitions using MacDrive. If I created a partition on Snow Leopard, Windows could see it and write to it. No problem.

Now when I boot into Snow Leopard, I cannot change my hard drive layout at all in Disk Utilities. SL sees the hard drive as "MBR". Is there anyway I can reverse all of this?

gdisk (for Windows) sees the missing partitions, however "Disk Management" sees it all as "Unallocated".

Oh, if SL also see it as MBR then it's not good. Your Win startup repair messed with your GPT/hybrid disk.

I'm not sure I can help you with that then. If I were you I would first try to make a backup of the whole disk (if possible).  And then would play with gdisk and try to restore all partitions. If gdisk can see all partitions, maybe secondary (backup) GPT partition table is still there and gdisk can recover the disk. Read carefully gdisk pages. Check here: http://www.rodsbooks.../repairing.html specially "Overwritten GPT main header or table".

Wish you luck.

EDIT:
Better to do all gdisk stuff from some Linux live CD/USB or another disk if you have it. And if you manage to get back all partitions on a GPT disk, do not forget to create hybrid from it (add needed partitions to MBR, again with gdisk) in order to be able to boot Win 7.