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Scotch_Brawth Author

Level 3

827 points

Repairing Boot Camp after creating new partition

I'm running OS X 10.8 and Windows 7 x64 Pro.

After properly setting up Boot Camp to dual-boot Windows on my Mac mini, I decided to test whether or not it was true that creating another partition (a data partition for OS X) would interfere with Boot Camp. Wikipedia claims it does interfere but without citing a source, whilst the Boot Camp documentation itself only specifies that the disk must be a single partition _prior_ to setup - there's no mention of whether the disk must be _kept_ that way afterwards.

I opened Disk Utility, reduced the size of my OS X parition from 420GB to 80GB, and created a new partition in the unallocated space. Here's how it looks now:

When I attempted to proceed with the process, I did receive a warning that doing this (and I quote), "may" cause problems with Boot Camp. Seeing as it was inconclusive, I thought I'd give it a shot - nothing ventured…

Of course, it borked Boot Camp, otherwise I wouldn't be posting here. Whilst OS X boots just fine, the Boot Camp partition now no longer shows up in the Startup Manager, though it does in the Startup Disk prefPane. If I do attempt to boot into Boot Camp, I receive the following message on a black screen:

No bootable device --- insert boot disk and press any key

The advice given to someone who had this same problem was, "fix your damaged Boot Camp volume." But I'm at a loss as to how to do that.

So, anyone know how to proceed now so that I can keep my partitions as is, whilst fully restoring normal Boot Camp functionality?

Mac mini (Mid 2011), Mac OS X (10.7.4)

Posted on Jul 26, 2012 11:28 PM

1,534 replies

Loner T

Level 9

59,513 points

Jul 25, 2014 10:59 AM in response to MattTheMedic

There is another thread in Repairing Boot Camp after creating new partition here which has the same issue and solution.

Loner T

Level 9

59,513 points

Jul 25, 2014 11:19 AM in response to Loner T

Please be advised for any one attempting Yosemite on the same disk which also contains Bootcamp.

Yosemite, Bootcamp and Mavericks MUST not be installed on a Mac which has either a single disk, or on a disk that has more than one visible partition (via Disk Utility).

Orinks

Level 1

0 points

Jul 25, 2014 11:16 AM in response to Loner T

Unfortunately, I tried this with a dev version of Yosemite, and messed it up. Now, when I go to erase this partition, even in recovery, it simply will not remove itself. I have the beta on the main HD and have Mavericks as a Time Machine backup if it comes to that.

Can anyone help with this? Perhaps if I can get this partition removed it'll be four partitions again, including EMI.

Thank you.

Loner T

Level 9

59,513 points

Jul 25, 2014 11:23 AM in response to Orinks

I waited for you to start a new thread. 😉 Please post the output of the commands in a new thread and post a reference to that thread here.

diskutil list

sudo fdisk /dev/<DiskNameOfYourBootcamp>

sudo gpt -vv -r show /dev/<DiskNameOfYourBootcamp>

Jul 29, 2014 7:28 PM in response to Scotch_Brawth

Hi, I have partitioned my HD into 2 partitions, but now I can't boot Bootcamp ( I've already deleted the extras partitions), if someone can help me out, i created a separated thread for my problem

Bootcamp not bootable after partitioning disk

Orinks

Level 1

0 points

Jul 31, 2014 7:15 AM in response to johnmax345

Hi all,

So I'm having trouble starting new threads here, when I ask a question in that search area I get that submit this question to the community and it only appears for a few seconds it seems.

So, I'm attempting to follow the steps in post two, but when I add partition five to the new MBR, I get the following message:

Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N):

What does this mean? I'd start my own thread, but recently I've been having trouble with it and merging threads is a pain with VoiceOver on this site.

Loner T

Level 9

59,513 points

Jul 31, 2014 9:38 AM in response to Orinks

The MBR supports only 4 partitions. Adding the EFI partition is done automatically by disk, so the answer here is Y(es).

Aug 1, 2014 2:27 AM in response to Christopher Murphy

I'm having trouble with my Windows Partition after resizing it, I would really appreciate your expertise on this please.

This is what the following has produced:

sudo fdisk /dev/disk0

Admins-MacBook-Pro:~ admin$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 38913/255/63 [625142448 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 0 0 2 - 25 6 46 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 115234776] HFS+

*3: 07 1023 6 63 - 1023 6 63 [ 115644416 - 204800] HPFS/QNX/AUX

4: 07 1023 6 63 - 1023 6 63 [ 115849216 - 509290496] HPFS/QNX/AUX

Admins-MacBook-Pro:~ admin$ sudo fdisk /dev/disk0

Password:

Sorry, try again.

Password:

Disk: /dev/disk0 geometry: 38913/255/63 [625142448 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 0 0 2 - 25 6 46 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 115234776] HFS+

*3: 07 1023 6 63 - 1023 6 63 [ 115644416 - 204800] HPFS/QNX/AUX

4: 07 1023 6 63 - 1023 6 63 [ 115849216 - 509290496] HPFS/QNX/AUX

sudo gdisk -l /dev/disk0

Admins-MacBook-Pro:~ admin$ sudo gdisk -l /dev/disk0

GPT fdisk (gdisk) version 0.8.10

Warning: Devices opened with shared lock will not have their

partition table automatically reloaded!

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Disk /dev/disk0: 625142448 sectors, 298.1 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 00002E2B-6432-0000-C80D-00009C2B0000

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 625142414

Partitions will be aligned on 8-sector boundaries

Total free space is 509498005 sectors (242.9 GiB)

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

1 40 409639 200.0 MiB EF00 EFI system partition

2 409640 115644415 54.9 GiB AF00 Customer

Loner T

Level 9

59,513 points

Aug 1, 2014 5:02 AM in response to J Elliot2014

Please start a new thread and post a reference to the new thread here. Re-sizing Bootcamp Windows is not supported as Apple implements it using a Hybrid MBR.

Aug 1, 2014 4:47 PM in response to Loner T

Thank you for the reply Loner T.

Please see the link below:

Lost windows partition after resizing bootcamp

Harlune

Level 1

0 points

Aug 4, 2014 11:56 PM in response to J Elliot2014

Hello people smarter than me. I seek knowledge and skills I do not posses. I replaced my SSD with a bigger one going from 240gb to 960gb. The old one had two bootcamp OS partitions (Mac, Windows) and four partitions (EFI System Partition, Recovery HD make up the remaining two) I added a third (5th) partition that I labeled scratch (ExFat) that I intend to be a bulk storage for assets. Currently it will boot MacOS but not Windows 7.

My end goal is:

240gb [Bootable, Mac OS Extended (Journaled), MacOS X, MacLandia-new]

240gb [Bootable, NTFS, Windows 7, Winlandia-N]

480gb [ExFAT, Scratch]

Output from "sudo gpt -r -vv show disk0"

gpt show: disk0: mediasize=960197124096; sectorsize=512; blocks=1875385008

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: error: bogus map

gpt show: unable to open device 'disk0': No such file or directory

Output from "sudo fdisk /dev/disk0"

Disk: /dev/disk0 geometry: 116737/255/63 [1875385008 sectors]

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 - 487274680] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 487684320 - 1269536] Darwin Boot

4: 07 1023 254 63 - 1023 254 63 [ 488953856 - 509388800] HPFS/QNX/AUX

Output from "gdisk"

Disk /dev/disk0: 1875385008 sectors, 894.3 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 151BF613-9829-4D05-87C8-1C064CF8AB85

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 1875384974

Partitions will be aligned on 8-sector boundaries

Total free space is 342059669 sectors (163.1 GiB)

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

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 487684319 232.4 GiB AF00 MacLandia-new

3 487684320 488953855 619.9 MiB AB00 Recovery HD

4 488953856 635437055 69.8 GiB 0700 Winlandia-N

5 977496064 1875384319 428.1 GiB 0700 scratch

Loner T

Level 9

59,513 points

Aug 5, 2014 4:51 AM in response to Harlune

Please start a new thread, paste the output in that thread and post a reference back here. It is a bit easier to keep track that way.

One additional output that would help is (the disk slice can be seen in diskutil list).

sudo dd if=/dev/<BootcampDiskSlice> count=1 2>/dev/null | hexdump -C

Aug 5, 2014 7:37 PM in response to Loner T

As per request, my new thread is here with output included:

Repair Boot Camp Partition

I am also having some basic issues installing gdisk (Not sure if I have wrong installer)

Can someone please help.

Aug 11, 2014 6:26 AM in response to Christopher Murphy

This fixed my Win8 installation. My Yosemite adventures probably messed up Bootcamp. Thanks for the help!

Aug 11, 2014 9:55 AM in response to Loner T

Hi:

First, I wanted to thank you all for helping the many plagued by this problem. It's hard to believe that this thread started on July 26, 2012!

So, I too lost ability to use Bootcamp to start Windows 7 when I upgraded to Mavericks on my 27 iMac (EFI 1.10). I see that I have too many entries in my GPT and so a hybrid MBR needs to be recreated. Before I do that, I'm wondering whether I should delete the second OSX partition that I never use. My NTFS partititon is intact, readable and has been backed up to a Winclone image.

Here's a link to a new thread I started:

Lost Win7 in BootCamp, should I rearrange partitions before fixing MBR?

Thanks!

Repairing Boot Camp after creating new partition