Repairing Boot Camp after creating new partition

Any OSX upgrade is likely to dislike what it finds in the MBR and over-write it.

Number88 wrote:

Any OSX upgrade is likely to dislike what it finds in the MBR and over-write it.

Interesting. I suppose as long as gdisk can do its mojo, that's survivable. And everything in the Windows partition is optional.

A normal OS X + Windows install has a total of four partitions. If you use Disk Utility to repair the whole drive (not merely a volume), it will replace the hybrid MBR with a protective one, with your 6 partition configuration, and you won't be able to boot Windows until you recreate the non-standard hybrid MBR. So it's not just a future OS upgrade that could break things. I suggest vigilant backups.

Christopher Murphy wrote:

A normal OS X + Windows install has a total of four partitions. If you use Disk Utility to repair the whole drive (not merely a volume), it will replace the hybrid MBR with a protective one, with your 6 partition configuration, and you won't be able to boot Windows until you recreate the non-standard hybrid MBR. So it's not just a future OS upgrade that could break things. I suggest vigilant backups.

Thanks! On the surface it looks like this is no more (or less) dangerous than having Bootcamp on partition 5 and using gdisk to make the non-standard HMBR. Am I missing a subtle distinction there?

The MBR can only hold 4 partitions so having 6 is just as non-standard as having 5.

Bootcamp is "normally" on partition 4.

It's varying degrees of fragility. No hybrid MBR is stable. A hybid MBR is more fragile, but relatively stable if there are only four total partitions. As soon as you have 5 or more, you're off the rails. So just don't let anything change partition sizes, add or remove them. Ever. Until you're ready to lose all data. And then if it ends up somehow working out, consider it a bonus.

Hi Christopher - You seem like the guru with regards to this

I'm having a similar problem here: Any chance of you having a look at the problem. Much appreciated

https://discussions.apple.com/thread/6014260?answerId=25232609022#25232609022

Hi Chris,

I had the same problem in this post mentioned. Hopefully, I can boot up windows 8.1 with the steps and result you mentioned. Except....I can only see the Windows partition when I boot it up and cannot choose neither OSX or Recovery partition. I cannot read through the content of Mac drive as well. Here is the display of gdisk with windows. Look forward your comment. Thanks.

Command (? for help): p

Disk 0:: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): EAAAD34C-E30F-47B2-8463-1C900514EEA7

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 976773134

Partitions will be aligned on 8-sector boundaries

Total free space is 589 sectors (294.5 KiB)

Number Start (sector) End (sector) Size Code Name

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 622917287 296.8 GiB AF00 Mac_Mou.Lion

3 622917288 624186823 619.9 MiB AB00 Recovery HD

4 624187392 781461503 75.0 GiB 0700 EXFAT

5 781461504 976773119 93.1 GiB 0700 BOOTCAMP

Command (? for help):

what if i re-create the hybrid MBR??

Thanks.

Can you post the output of the current MBR (sudo fdisk /dev/[r]disk<n>)?

Hi Christopher, and anyone else who can help.

I'm afraid I've fallen into the same trap as those before me, using Disk Utility to decrease the size of my OS X partition, with a view to then increasing my Windows 8 parition – which of course I could not boot to after resizing the OS X partition. All files are backed-up from my windows partition, so it's no problem if I have to ultimately re-install.

I'm using 10.6.8 (Snow Leopard) and Windows 8. (Mid 2010 MacBook Pro, 512Gb SSD)

1 OS X Partition, 1 Windows 8 Partition.

I've read as much of this thread as I can, and followed the guidlines to repair. It seemed to work, but when I tried to boot windows, i got the "missing operating system" message – as I have seen a few people get here.

Following the advice given here i repeated the process, making a new hybrid MBR adding 2 and 3 to it, with 3 being bootable. To no avail, I get the same "missing operating system" error.

Can anyone advise on what to try next? If it looks like my windows is completely trashed, what is the safest way to return my OS X drive to its full capacity (512Gb) and then re-install Bootcamp?

Here is the state of things now (below). I can provide more info if needed. I've tried to be concise.

Have you tried Windows Recovery Console (bootrec.exe)?

http://support.microsoft.com/kb/927392/en-us

Thanks for the prompt reply!

I wasn't sure whether to try that next, or attempt other things with gdisk first.

I'll try the recovery console. I'm assuming to access it I put my windows DVD in and boot from DVD? (I guess i'll find out in 5 mins...)

I'll let you know how it goes!

When I boot from CD, it gets to the message 'press any key to boot from CD...' but when I press a key, my good old friend 'missing operating system' returns!

So as it stands, I cannot get access to the windows recovery console.

Is there another way to access it, or launch it on my computer?

Please look here - https://discussions.apple.com/thread/5646583?answerId=24073035022#24073035022

The DD command should help.

http://www.techspot.com/news/48718-windows-8-removes-need-for-f8-key-advanced-bo ot-menu-redesigned.html

The wonders of the F8 key are gone. Since you use W8+, try the shift key.