Repairing Boot Camp after creating new partition

I have another question related to this. Will just using gparted convert the hybrid MBR into a protective MBR, or do I have to edit the partition table to do that?

gparted uses parted, which upon altering a GPT will always remove the hyrid MBR and replace it with a protective MBR.

I know that, but does it remove the hybrid MBR just by viewing the disk?

It shouldn't. In my experience so far, if the first MBR entry is type 0xEE, then parted ignores the MBR in favor of the GPT, and shows the GPT without modifying either MBR or GPT until you tell it to (I think it uses the word Apply).

Hello Christopher -

I have this same problem but I am concerned about changing the hybrid MBR settings. Do you always use "5" while in gdisk?

Edit: Sorry replied to wrong post! X/

Hello Christopher -

I have this same problem but I am concerned about changing the hybrid MBR settings. Do you always use "5" while in gdisk?

No, it depends on the GPT partition you're trying to add to the MBR. So you first need to know which GPT partition is the Windows partition.

Also, this is only one possible way to do it, with 5 partitions, but it's the safest. Since your OS X partition is not added to the MBR, it means Windows won't see it, and therefore you can't read files from the OS X partition while you're booted in Windows. There is a work around for this, by adding the OS X partition to the MBR also, but if you do that, the MBR won't have enough slots to protect all of your other partitions so something will have to be left out of the MBR and therefore it will appear to be free space to Windows and Windows apps - making that partition susceptible to being overwritten. That's why for 5+ partition layouts, I recommend just adding the Windows partition to the MBR, and giving up on read/write to the OS X partition.

Another valid layout which is pretty safe, is if the 4th/5th GPT partitions are both Windows formatted volumes (NTFS or FAT32), you can add them both to the MBR. But you need to make sure you mark the correct partition as bootable in gdisk, which is the partition that actually has Windows installed on it.

Okay so the outputs from the two commands that you asked Scotch to do are:

sudo gpt -r -vv show disk0

gpt show: disk0: mediasize=500277790720; sectorsize=512; blocks=977105060

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 977105059

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 647656248 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

648065888 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

649335424 1408

649336832 76953600 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

726290432 250814464 5 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

977104896 131

977105027 32 Sec GPT table

977105059 1 Sec GPT header

sudo fdisk /dev/disk0

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 - 647656248] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 648065888 - 1269536] Darwin Boot

4: 0B 1023 254 63 - 1023 254 63 [ 649336832 - 76953600] Win95 FAT-32

What would I do in this situation?

You'd add partitions 4 and 5 to the MBR, and flag one of them as bootable. Both of those partitions use the GUID for Windows file systems, but there's nothing that says which one contains Windows. But partition 4 is the smaller of the two.

Christopher Murphy wrote:

You'd add partitions 4 and 5 to the MBR, and flag one of them as bootable. Both of those partitions use the GUID for Windows file systems, but there's nothing that says which one contains Windows. But partition 4 is the smaller of the two.

@Christopher... This thread has turned into the 'Ask Christopher Murphy about Bootcamp and Partitioning' thread. It is wonderful to see such community support. My hat off to you Christopher, for such support. Perhaps this will become the longest running thread on this forum. 😎

Hi Christopher - and the rest of you all 😉

Just been reading the first two pages and planning to read it out from 1-24 coming days!

GREAT 1st solution and info's here!!!!!

I have the same problem running OS X 10.8.2 and installed WIN8PROx64 with Bootcamp 5.0 resulting in:

1. a OS X system that shows no Windows boot-disk in System Prefs;

2. needed to un-install the BootCampServices in Windows for it gave me the first BSOD!

Since working with the MAC since 2008 I totally forgot what that looked like ;-)

Now it's with a ;( wich I think is very nice of Bill and telling me I had to GooGle for cache_manager problems...

3. some random very slow boot-ups with both OS's

So after making a CCC bootable image on an external FW-HDD and a Windows back-up on another FW-HDD, I'll give this a sling shot!

Keep you posted!!!

Cheers to all writers and readers in this GREAT thread!

Thank you so much Christopher Murphy, this just saved my life.

On my MacBook Pro I have BootCamp partition to boot Windows, and in Mac partition I had to create a CaseSensitive partition for CaseSensitive MySQL database, and then I could not boot in Windows anymore.

I follow all the instructions using the gdisk utility and all is fine again.

I found this after searching for hours and tearing my hair out.

Super happy now.

Thanks!

Hi Chriopher,

Great reading from the first few pages!

Last login: Wed Jan 9 21:39:47 on ttys000

$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI 209.7 MB disk0s1

2: Apple_HFS MAC_OSX_ML 499.0 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data WIN8_PROx64 500.3 GB disk0s4

$ sudo gpt -r -vv show disk0

Password: [...]

gpt show: disk0: mediasize=1000204886016; sectorsize=512; blocks=1953525168

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Bad CRC in GPT table at sector 2

gpt show: disk0: Sec GPT at sector 1953525167

start size index contents

0 1 MBR

1 409639

409640 974609344 2 MBR part 175

975018984 1269536 3 MBR part 171

976288520 1272

976289792 977233920 4 MBR part 7

1953523712 1423

1953525135 32 Sec GPT table

1953525167 1 Sec GPT header

$ diskutil resizevolume /dev/disk0s2 limits

For device disk0s2 MAC_OSX_ML:

Current size: 499.0 GB (498999984128 Bytes)

Minimum size: 456.8 GB (456793563136 Bytes)

Maximum size: 499.0 GB (498999984128 Bytes)

$ sudo gdisk /dev/disk0

GPT fdisk (gdisk) version 0.8.5

Caution! After loading partitions, the CRC doesn't check out!

Warning! Main partition table CRC mismatch! Loaded backup partition table

instead of main partition table!

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: damaged

Found valid MBR and corrupt GPT. Which do you want to use? (Using the

GPT MAY permit recovery of GPT data.)

1 - MBR

2 - GPT

3 - Create blank GPT

Your answer: {one moment please, I'll have to ask Christopher for this one!!!!}

HOUSTON, Do I have a problem??????? 😮

Leaving my MAC running in terminal mode for now.........

One More Thing: Yes, this is rocket sience for me! 😕

Cheers!

Hi Christopher,

Tried to restore both Win and OSX:

1. So I installed a fresh 1TB HDD in bay#1

2. Booted in Recovery Disk mode on my bootable FW external CCC Backup

3. Format the new drive using Disk Utils in HFS Macintosh HD

4. Installed OS X 10.8.2 download from store

5. Installed GDISK

6. Used the same commands as above post and...(. From sector 1 there seems to be PRI GPT's which are not present on my BC disk I removed!)

7. Because I want to restore a Win backup I last made yesterday I used bootCamp 5.0.0 to make the MBR for OSX and Win

8. Because the BC 5 formats the disk FAT32 (backup is NTFS) I used Disk Utils to reformat the BOOTCAMP partition to NTFS (with Paragon NTFS for OSX latest version)

9. Checked again with GDISK and PRI GPT's from sector 1 are gone again giving me the caution's lusing gdisk as in above post again.

Is there a way to partition the BOOTCAMP partition in NTFS for restore backup without distroying the bootcamp MBR records? If so I can restore my OS X Using migration from CCC backup and the Win backup as well!

I hope my question does not seem offtopic as I want to use restore backup!

Thanks in advance!!!!

gpt show: disk0: Bad CRC in GPT table at sector 2

gpt show: disk0: Sec GPT at sector 1953525167

and

Main partition table CRC mismatch! Loaded backup partition table

instead of main partition table!

Yeah this is not good. But it implies the secondary GPT is OK. Gdisk will use the good one by default, so you should have gdisk spit out the GPT to the screen by typeing p then enter, and post that. I'd also go to the recover/transform menu, r then enter, and print out the MBR which is o then enter. And post that to the the forum. That way it's better understood if the backup GPT and MBR have agreeable entries. Once that's done and confirmed, you can then use gdisk to create a new hybrid MBR and write out the partition tables. When you do this, it will write a new clean MBR and GPT, including a replacement for the bad primary GPT.