Repairing Boot Camp after creating new partition

OK, I will try that, Thanks! If I am unsuccessful at repairing the exFAT data partition in Windows, your next recommendation for my needs would be to try to reformat as FAT32? Or format it as NTFS or HFS+ and use one of the third party utilities to enable read/write between operating systems?

Well my recommendation is to not use Boot Camp. I'd use a virtual machine, in which case you can share files between environments very easily and safely without having to mess around with partitions and file systems.

FAT32 will take a long time to repair if it gets particularly full with many files and you ever have a crash or power failure, because it lacks a journal. It also has a file size limit of 4GB, and volume limit of 2TB. So if those are problems you'll need to use HFS+ or NTFS. Between NTFS and HFS+ it's a coin toss. If these are just ordinary data files like word docs, spread sheets, images, movies, I would pick the 3rd party support solution that's the least expensive.

Hey Chris,

When I tried to make another Parition and I restarted my PC, It wouldn't boot into windows. When I made the partition, I called it Bootcamp2, when I booted up OSX when it wouldn't boot into windows I found MAC Evans 2 and disk0s4, I believe that disk0s4 is where bootcamp is stored, I checked this out with gdisk and partition 5 was marked as Bootcamp while 4 was marked as Mac Evans 2.

Mac Evans 2 is also empty and disk0s4 is unaccesable.

What I really want to ask is that if I follow your method on the first page, will it keep my data? When I was going through the steps at the end it tells me that it needs to delete all partitions?

I just want to make sure, and as for backing up, I can;t seem to backup disk0s4 with disk utility as it doesnt want to mount?

Please report the results from:

gdisk -l /dev/disk0

My suggestion is that you don't just start following directions meant for someone else, especially when I still don't have any idea how you got into this situation, or the state of your disk.

Here you go:

Administrators-MacBook-Air:~ administrator$ sudo gdisk -l /dev/disk0

Password:

GPT fdisk (gdisk) version 0.8.5

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Disk /dev/disk0: 490234752 sectors, 233.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 7CBAB763-7A10-4350-8803-0677E5B843FD

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 490234718

Partitions will be aligned on 8-sector boundaries

Total free space is 1469 sectors (734.5 KiB)

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

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 88342151 41.9 GiB AF00 Mac Evans

3 88342152 89611687 619.9 MiB AB00 Recovery HD

4 89612288 236054527 69.8 GiB 0700 MAC EVANS 2

5 236054528 490233855 121.2 GiB 0700 BOOTCAMP

Administrators-MacBook-Air:~ administrator$

Disk Utility is very confused. disk0s4 is Mac Evans 2, disk0s5 is BOOTCAMP. This might have to do with the discrepancy in between the MBR and GPT, and the fact the MBR is not defining the BOOTCAMP partition at all.

Use gdisk to create a new hybrid MBR. You'll go to the recovery/transformation menu to find the make new hybrid MBR option. You will add partitions 4 and 5 to the MBR, you'll say yes to putting EFI GPT first in the MBR, you'll accept the default partition type codes for those two partitions, and you'll say no to making partition 4 bootable, but you'll say yes to making partition 5 bootable. Then write out the changes with the 'w' command.

Ok, so Mac Evans 2 is Bootcamp? I can access Mac Evans 2 but it says it is empty? Also, will this method keep my data intact?

Mac Evans 2 is Bootcamp?

Umm, no. DiskUtility is reporting incorrectly. Partition 4 is Mac Evans 2. Partition 5 is Bootcamp. They are not the same thing.

Also, will this method keep my data intact?

I don't know how to answer that. The idea is to regain access to these two partitions for both Windows and OS X, and I've described how to do that. You could mess it up and make things worse, yes. But gdisk is designed to only edit partition tables, and those regions on disk have nothing to do with the partitioned regions that contain file systems and your data. You can completely zero the partition tables on the disk, and recreate them manually, and regain access to your data - they're different parts of the disk.

Anyway, what I suggest is that once you've made the new hybrid MBR, before you use the 'w' command to write the changes to disk, you can, from the Recovery/Transformation menu (be sure you are in that particular menu), use the 'o' and 'p' commands to print to screen the MBR and GPT. The changes you make when creating a new hybrid MBR are only in memory until you use the 'w' command. So you can post the results from the 'o' and 'p' command before using 'w' (just leave gdisk running in a hidden terminal, it doesn't hurt anything) if you want someone to proof read your results first.

I wanted to reply to thank you for your help. Your knowledge and advice have been extremely useful in understanding and troubleshooting this Windows/OSX partition management and such.

I looked into a utility to recover my exFAT drive, but didn't find anything that looked promising. Based on what you said about exFAT I decided to just reformat the data drive in HFS+ from OSX disk utility, and use Paragon on the Windows side to write to the disk. Although I had a terrible experience with Paragon before when writing to a folder stored on the OSX drive, I figure it can't hurt to give this a shot since it essentially took no time to do. I will give it a try for a few weeks to see how things go. If everything seems to work, I will consider this solution successful. If not, I will use the OSX repair utility to completely reformat the entire drive, reinstall OSX, and take your advice and go with a virtual machine.

In any case I will continue checking on this thread, and post back with any updates along the way. Thanks again for all of the help!

Hi Christopher,

I have a big question about my bootcamp partition.

It will not appears on start up, i cant boot in, also it can not be mount on disk utility.

Here is some information that you might requrie. What should i do? if the bootcamp cant be save at least i need the files inside.

my mac is a 2011-mid MBA

gpt show: disk0: mediasize=121332826112; sectorsize=512; blocks=236978176

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 236978175

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 42969264 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

43378904 1269544 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

44648448 192327680 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

236976128 2015

236978143 32 Sec GPT table

236978175 1 Sec GPT header

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 42969264] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 43378904 - 1269544] Darwin Boot

4: 0C 1023 254 63 - 1023 254 63 [ 44648448 - 192327680] Win95 FAT32L

GPT fdisk (gdisk) version 0.8.5

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Disk /dev/disk0: 236978176 sectors, 113.0 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 0000071A-1D08-0000-DA6B-0000FF0B0000

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 236978142

Partitions will be aligned on 8-sector boundaries

Total free space is 2021 sectors (1010.5 KiB)

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

1 40 409639 200.0 MiB EF00 EFI system partition

2 409640 43378903 20.5 GiB AF00 Machintosh HD

3 43378904 44648447 619.9 MiB AB00 Recovery HD

4 44648448 236976127 91.7 GiB 0700 BOOTCAMP

Any help would be appericated...

Ashley

Just another follow up, it can be use as target disk as well. When i chain up with a thunderbolt cable to a new macbook pro, the macbook pro will freeze in osx.

Hello Christopher,

since you say people shouldn't follow advice given for other people's situations, I think I'd rather ask you directly regarding my boot troubles. It's pretty much the usual case: Since I couldn't enlarge a Bootcamp partition after creation, I shrank my Mac OS X Partition (10.8.2) and formatted the unallocated space as an additional exFAT. This, of course, completely broke my ability to boot Windows 7.

Here are the results from the commands in Terminal:

gpt show: disk0: mediasize=320072933376; sectorsize=512; blocks=625142448
gpt show: disk0: Suspicious MBR at sector 0
gpt show: disk0: Pri GPT at sector 1
gpt show: disk0: Sec GPT at sector 625142447
      start       size  index  contents
          0          1         MBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6         
         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     409640  500000000      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  500409640    1269544      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  501679184   44923824         
  546603008   78538752      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  625141760        655         
  625142415         32         Sec GPT table
  625142447          1         Sec GPT header

Disk: /dev/disk0     geometry: 38913/255/63 [625142448 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 -     409639] 
 2: AF 1023 254  63 - 1023 254  63 [    409640 -  500000000] HFS+        
 3: AB 1023 254  63 - 1023 254  63 [ 500409640 -    1269544] Darwin Boot   4: 0C 1023 254  63 - 1023 254  63 [ 546603008 -   78538752] Win95 FAT32L

If you could tell me what exactly has gone wrong in my case I would be ever-so-grateful. :-)

Best regards,

Nate

Thank you so much for helping me, here are the results:

Recovery/transformation command (? for help): o

Disk size is 490234752 sectors (233.8 GiB)

MBR disk identifier: 0xB1886B2D

MBR partitions:

Number Boot Start Sector End Sector Status Code

1 1 89612287 primary 0xEE

2 89612288 236054527 primary 0x07

3 * 236054528 490233855 primary 0x07

Recovery/transformation command (? for help): p

Disk /dev/disk0: 490234752 sectors, 233.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 7CBAB763-7A10-4350-8803-0677E5B843FD

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 490234718

Partitions will be aligned on 8-sector boundaries

Total free space is 1469 sectors (734.5 KiB)

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

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 88342151 41.9 GiB AF00 Mac Evans

3 88342152 89611687 619.9 MiB AB00 Recovery HD

4 89612288 236054527 69.8 GiB 0700 MAC EVANS 2

5 236054528 490233855 121.2 GiB 0700 BOOTCAMP

Recovery/transformation command (? for help):

Looks good. So use the 'w' command to write out the new partition tables and reboot.

There is no enough information to answer your question.

4: 0C 1023 254 63 - 1023 254 63 [ 44648448 - 192327680] Win95 FAT32L

The BootCamp entry in the MBR is suspicious. 1.) It doesn't have the boot flag set. 2.) It has the FAT32 type code, not the NTFS type code. My first thought is that this partition has been formatted/erased, and is in fact FAT32, not NTFS. Windows 7 makes it very difficult to install on FAT32, as it wants to be installed on an NTFS volume. In any case, this volume should mount in OS X and if there's data on it, you should be able to back it up from within OS X.

You could try using gdisk to make a new hybrid MBR, and add partitions 2 3 4 to it, accepting the option to put EFI/GPT in the first MBR entry, and not setting the boot flag for partitions 2 and 3. But set the boot flag for partition 4. This will change the type code in the MBR for Bootcampt to 07, and set it as bootable. So if the volume is NTFS, not FAT32, this may work.