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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

Mar 18, 2013 1:46 AM in response to Christopher Murphy

I was just about to post in the Mac Mini forum, when I got the idea.

It wouldn't matter how badly the drive or NVRAM are misconfigured, zapping PRAM should always work.

So if I opened the Mini again and manually put the PRAM battery out and back in again, it should also do it.

Mar 18, 2013 8:39 AM in response to zoidb_1221

I'd wonder if the battery just needs to be replaced with a new one if that works though. I know these CMOS batteries were needed at one time to make the memory boot information was stored in non-volatile. But I don't know if that's still true, or if this battery is just for the clock when the computer is powered off. *shrug*

Mar 18, 2013 11:55 AM in response to Christopher Murphy

Well, it didn't work. Interestingly, the Mini sounded different when it started this time, but didn't get past the white yet again.

I started a thread in the Mini forum, so if anyone has a clue, I'm thankful for any help I can get.

Mar 19, 2013 9:04 PM in response to Christopher Murphy

Christopher: I just wanted to say thanks for helping me out! Your advice saved me a lot of bother!! My remaining issues have nothing to do with Bootcamp or partitioning. Furthermore, they are not urgent - I can figure them out and deal with them when I have time and need to do it, for the moment my Macbook works just fine.

Thanks!!

ThBo

Level 1

8 points

Mar 26, 2013 6:41 AM in response to Christopher Murphy

Christopher Murphy wrote:

Yes. Obviously I wouldn't have seen it so if you're trying to get my attention it's worth posting a link in this **** thread with a 1-2 line summary and maybe I'd poke my head in. Too late now, you have a plan to follow.

Could you please have a look at this thread https://discussions.apple.com/thread/4919881 ?

I have the problem that i temporarily detached a disk in my system to install Win 8 (since it doesnt allow to be installed on the second disk in a system) and after reattaching Windows doesnt boot anymore.

I would very much apreciate any suggestions. Think it is somewhat different to the problem in this thread so i followed the suggestion to make a new one. Thanks.

Apr 5, 2013 5:42 AM in response to Scotch_Brawth

Hi Christopher, I have a similar problem. Do you mind helping me walk through this. This is what I got from the first 2 things you said to do:

stevembp17:~ steve$ sudo gpt -r -vv show disk0

gpt show: disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 976773167

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 916015616 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

916425256 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

917694792 1720

917696512 59076608 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

976773120 15

976773135 32 Sec GPT table

976773167 1 Sec GPT header

stevembp17:~ steve$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 60801/255/63 [976773168 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: AC 1023 254 63 - 1023 254 63 [ 409640 - 916015616] <Unknown ID>

3: AB 1023 254 63 - 1023 254 63 [ 916425256 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [ 917696512 - 59076608] HPFS/QNX/AUX

I have gdisk installed.

GPT fdisk (gdisk) version 0.8.6

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Build 12C60

Since I've never done this before, I hope you can assist me in continuing.

steve

Apr 5, 2013 8:47 AM in response to f11music.com

stevembp17:~ steve$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk0

1: EFI 209.7 MB disk0s1

2: Apple_CoreStorage 469.0 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data BOOTCAMP 30.2 GB disk0s4

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Macintosh HD 500 *468.7 GB disk1

/dev/disk2

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk2

1: EFI 209.7 MB disk2s1

2: Apple_HFS MacBookPro17 BU 1TB 999.9 GB disk2s2

AND

GPT fdisk (gdisk) version 0.8.6

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Command (? for help): p

Disk /dev/disk0: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 403B4C42-CAB6-45AC-B976-321C29FA1772

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 1741 sectors (870.5 KiB)

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

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 916425255 436.8 GiB AF05 Macintosh HD 500

3 916425256 917694791 619.9 MiB AB00 Recovery HD

4 917696512 976773119 28.2 GiB 0700 BOOTCAMP

Apr 5, 2013 9:01 AM in response to f11music.com

Going further…

Recovery/transformation command (? for help): h

WARNING! Hybrid MBRs are flaky and dangerous! If you decide not to use one,

just hit the Enter key at the below prompt and your MBR partition table will

be untouched.

Type from one to three GPT partition numbers, separated by spaces, to be

added to the hybrid MBR, in sequence: 4

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

Creating entry for GPT partition #4 (MBR partition #2)

Enter an MBR hex code (default 07):

Set the bootable flag? (Y/N): y

Unused partition space(s) found. Use one to protect more partitions? (Y/N): n

Recovery/transformation command (? for help): o

Disk size is 976773168 sectors (465.8 GiB)

MBR disk identifier: 0x2F36CD85

MBR partitions:

Number Boot Start Sector End Sector Status Code

1 1 917696511 primary 0xEE

2 * 917696512 976773119 primary 0x07

Recovery/transformation command (? for help):

Recovery/transformation command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING

PARTITIONS!!

Do you want to proceed? (Y/N): y

OK; writing new GUID partition table (GPT) to /dev/disk0.

Warning: The kernel may continue to use old or deleted partitions.

You should reboot or remove the drive.

The operation has completed successfully.

stevembp17:~ steve$

Apr 11, 2013 1:48 AM in response to Christopher Murphy

Hello Christopher:

Sounds like you are like a rockstar so praying you'll be able to rescue my partition!!

This is what I did

a) Created a Win 7 bootcamp partition

b) Installed Windows 8

c) Installed VMware

2 Issues:

1.- Although I'm perfectly able to run Win8 as a VM ONLY, If I try to boot my Mac computer with Win8, it doesn't load and crashes (get like a blue death screen)

2.- I'm unable to get Winclone to backup my bootcamp partition since Mac sees bootcamp partition as "FAT" partition, even though it's reported as NTFS in Windows. I do recall I installed rEFIT and tried to use its utilities this but never fixed this so I deleted rEFIT. This issue is more important than the first one.

Pls take a look at my stuff:

GPT

gpt show: disk0: mediasize=251000193024; sectorsize=512; blocks=490234752

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 490234751

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 390624992 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

391034632 262392

391297024 98936832 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

490233856 863

490234719 32 Sec GPT table

490234751 1 Sec GPT header

MBR STUFF

Disk: /dev/disk0

geometry: 30515/255/63 [490234752 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 - 390624992] HFS+

3: 0B 1023 254 63 - 1023 254 63 [ 391297024 - 98936832] Win95 FAT-32

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

DISKUTIL STUFF:

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 200.0 GB disk0s2

3: Microsoft Basic Data BOOTCAMP 50.7 GB disk0s3

**************************

What should I do to fix those two issues?? Please help

Thanks!

-Ed

May 11, 2013 6:23 AM in response to Christopher Murphy

Hi Christopher, I am writing to you as you seams to be THE guy resolving all these problems 😀

I also have a MBR / GPT / Dual boot problem, and having a system on two different disk, I am unable to find any reference in this post.

I created a new thread here. https://discussions.apple.com/thread/5029283

I would be glad if you could help!

Thanks.

Jun 2, 2013 3:25 PM in response to f11music.com

I'm not sure what the problem is that you're having, but the two partition tables are in parity. I see no problem with them.

atiface

Level 1

0 points

Jun 3, 2013 8:45 PM in response to Scotch_Brawth

Hi Christopher

Wondering if you can help me too

Fdisk results are :

Disk: /dev/disk0

geometry: 30515/255/63 [490234752 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 0 0 2 - 1023 254 63 [ 1 - 245821439] <Unknown ID>

*2: 07 1023 254 63 - 1023 254 63 [ 245821440 - 244412416] HPFS/QNX/AUX

3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

GPT results are

gpt show: disk0: mediasize=251000193024; sectorsize=512; blocks=490234752

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 490234751

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 244200544 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

244610184 1211256 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

245821440 244412416 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

490233856 863

490234719 32 Sec GPT table

490234751 1 Sec GPT header

I ran the commands for gdisk with the index of 4 but it has not worked so far.

Really appreciate if you could have a look and tell me what I am doing wrong.

Regards

Atif

Mannsy

Level 1

0 points

Jun 4, 2013 3:28 AM in response to Christopher Murphy

Hi Christopher,

You seem like you might be the one person who can help me!

Please see my thread:

https://discussions.apple.com/thread/5078810?answerId=22160031022#22160031022

Any help you can offer would be massively appreciated!

Jun 5, 2013 4:42 PM in response to Christopher Murphy

Christopher Murphy, you are AWESOME. Fixed my iMac 27 with your steps + rEFIt. Well, ONE of my FIVE bad iMac 27's (part of the Seagate recall program). I am ETERNALLY grateful. Your steps made Boot Camp show up at startup but gave me a blinking cursor, then rEFIt made it boot.

One note for those trying rEFIt: it doesn't kick in until the second restart; I initially gave up on it, then the next morning rEFIt magically appeared at start, and Boot Camp magically booted. But it fixed something, because even after I uninstalled rEFIt, the fix persists.

I'm still working on #2 - the one that actually failed - and it did NOT respond to the same steps. But sfc /scannow is failing to repair some files on that one, so that may be the problem, but it's still stuck at the blinking white cursor stage. See my other thread: https://discussions.apple.com/thread/4932822

Jun 11, 2013 9:23 AM in response to Christopher Murphy

There are some obscure problems around but this takes the prize. I waited 8 days for my Windows 8 DVD expecting it to fix my bootcamp partition to no avail. I stumbled upon this I second Scotch_Brawth and nominate you for a haggis award, with honours! I can now access my Windows 8 partiton. Many thanks

Repairing Boot Camp after creating new partition