"Missing Operating system_ " After installing Yosemite

Not an expert in this matter but, when I had the issue I booted the MAC with Yosemite on a USB drive and ran a Verify on the Hard Drive. Are you able to boot into MAC? If so try recreating your Boot Camp.

Thanks bro...

Everything is fine on the Mac side. But the Bootcamp partition is gone 😟

The first screen shot shows a large gap between GPT3 and GPT4. Can you post the output of sudo gpt -vv -r show /dev/disk0? This is a Yosemite upgrade bug.

You will most likely need Testdisk to look for your 'lost' NTFS header and Windows partition.

Please see Bootcamp partition has disappeared after upgrade to Yosemite 10.10 for steps.

Dear Loner T

Here is the output of

sudo gpt -vv -r show /dev/disk0

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

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 1953525167

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 879526024 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

879935664 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

881205200 485709872

1366915072 586608640 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

1953523712 1423

1953525135 32 Sec GPT table

1953525167 1 Sec GPT header

I would appreciate any instructions of what steps to follow. 🙂

Thanks for taking the time to help everyone.

Do you have Testdisk and GPT Fdisk (disk) already installed? If Testdisk is installed, please start it using

sudo testdisk /dev/rdisk0 and

Create, Analyse, Pick EFI partition, Quick Search.

Hi Loner T,

I tried to follow the instructions...

Now the windows partition shows up when I hold the alt key on startup but when I try to boot from windows I get a "cannot read disk" message.

Any help would be most appreciated.

TestDisk 7.0-WIP, Data Recovery Utility, October 2014

Christophe GRENIER <grenier@cgsecurity.org>

http://www.cgsecurity.org

Disk /dev/disk0 - 1000 GB / 931 GiB - 1953525168 sectors (RO)

Current partition structure:

Partition Start End Size in sectors

1 P EFI System 40 409639 409600 [EFI System Partitio

2 P Mac HFS 409640 879935663 879526024 [Customer]

3 P Mac Boot 879935664 881205199 1269536 [Recovery HD]

Warning: number of heads/cylinder mismatches 255 (NTFS) != 1 (HD)

Warning: number of sectors per track mismatches 63 (NTFS) != 1 (HD)

4 P MS Data 1366915072 1953523711 586608640 [Microsoft basic dat

a]

P=Primary D=Deleted

>[Quick Search] [ Backup ]

Try to locate partition

TestDisk 7.0-WIP, Data Recovery Utility, October 2014

Christophe GRENIER <grenier@cgsecurity.org>

http://www.cgsecurity.org

Disk /dev/disk0 - 1000 GB / 931 GiB - 1953525168 sectors (RO)

The harddisk (1000 GB / 931 GiB) seems too small! (< 1300 GB / 1211 GiB)

Check the harddisk size: HD jumpers settings, BIOS detection...

The following partitions can't be recovered:

Partition Start End Size in sectors

> MS Data 1953523711 2540132350 586608640

Mac HFS 1953525124 1954794659 1269536

[ Continue ]

NTFS, blocksize=4096, 300 GB / 279 GiB

TestDisk 7.0-WIP, Data Recovery Utility, October 2014

Christophe GRENIER <grenier@cgsecurity.org>

http://www.cgsecurity.org

Disk /dev/disk0 - 1000 GB / 931 GiB - 1953525168 sectors (RO)

Partition Start End Size in sectors

>P EFI System 40 409639 409600 [EFI]

P Mac HFS 409640 879935663 879526024

P Mac HFS 879935664 881205199 1269536

D MS Data 881205248 1953523704 1072318457

D MS Data 1366915072 1953523711 586608640

D Mac HFS 1952255592 1953525127 1269536

Structure: Ok. Use Up/Down Arrow keys to select partition.

Use Left/Right Arrow keys to CHANGE partition characteristics:

P=Primary D=Deleted

Keys A: add partition, L: load backup, T: change type, P: list files,

Enter: to continue

FAT32, blocksize=512, 209 MB / 200 MiB

Directory structure seems to be there...

TestDisk 7.0-WIP, Data Recovery Utility, October 2014

Christophe GRENIER <grenier@cgsecurity.org>

http://www.cgsecurity.org

MS Data 881205248 1953523704 1072318457

Directory /

>dr-xr-xr-x 0 0 0 13-Nov-2014 03:16 .

dr-xr-xr-x 0 0 0 13-Nov-2014 03:16 ..

dr-xr-xr-x 0 0 0 5-Mar-2013 03:17 $AVG

dr-xr-xr-x 0 0 0 5-Mar-2013 00:54 $Recycle.Bin

dr-xr-xr-x 0 0 0 21-Dec-2013 01:10 .Trashes

dr-xr-xr-x 0 0 0 15-Jul-2013 23:56 Archbold Digital Edition

dr-xr-xr-x 0 0 0 15-Jul-2013 23:56 BlackstonesCriminalPractice2

dr-xr-xr-x 0 0 0 25-Jun-2014 03:48 Boot

dr-xr-xr-x 0 0 0 13-Nov-2014 03:16 Config.Msi

dr-xr-xr-x 0 0 0 29-Jun-2014 15:37 DCIM

dr-xr-xr-x 0 0 0 6-Jul-2014 23:56 Databases

dr-xr-xr-x 0 0 0 25-Jan-2014 17:53 GOG Games

dr-xr-xr-x 0 0 0 27-Apr-2014 13:06 Games

dr-xr-xr-x 0 0 0 5-Mar-2013 01:02 Intel

Next

Use Right to change directory, h to hide Alternate Data Stream

q to quit, : to select the current file, a to select all files

C to copy the selected files, c to copy the current file

This is excellent work.

PhivosZ wrote:

881205200 485709872

1366915072 586608640 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

This is what Testdisk found. The offset is positive and 48 bytes. The three numbers are start/end/size from the Testdisk output.

MS Data 881205248 1953523704 1072318457

A small table to verify that everything is clean.

The 'Byte Offset' being positive is good. A negative value means you lose GPT#3.

You need to use the following steps. If you see any error messages during the following steps, please stop and post back here with the error message.

Rebuild using start/end offsets from Testdisk DeepSearch using GPT Fdisk (http://sourceforge.net/projects/gptfdisk/)

1. Sudo gdisk /dev/rdisk0
2. P (print the full list of parts)
3. D (delete)
4. 4 (part 4)
5. N (new part)
6. 4 (part 4)
7. 881205248 - Start offset in bytes (start point for Bootcamp part)
8. +1072318457 (Size offset as opposed to End offset)
9. 0700 (Windows part type)
10. P (print list of all parts just to see what changes will be made)
11. W (Write the new GPT)
12. Y (Yes! really write the new GPT)

This will delete and re-write the GPT partition info for /dev/disk0s4.

Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR

1. Sudo gdisk /dev/disk0
2. P (Print list of parts)
3. R (Recover)
4. H (chooses Hybrid)
5. Partitions numbers to be hybridized: 2 3 4
6. Y (Good for GRUB question)
7. N (part 2 flag)
8. N (part 3 flag)
9. Y (part 4 flag make bootable partition)
10. W (Write the new MBR)
11. Y (Yes! write the new MBR)
12. Reboot

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

If you see a hanging underline cursor at the top left on a black screen, and it does not proceed further, you may need Windows Startup Repair or a tool called EasyBCD.

Loner T

Thank you thank you thank you thank you thank you thank you thank you thank you!

You rock man!

Everything is working now.

I am really really grateful for your help 🙂

Phivos

Excellent work PhivosZ.🙂

Hi Loner T,

I have the same Problem, but first I tried to repair my Win with the win 8 boot disc and the command (fix boot and fixmbr)

Now I have the Problem that I can't get any Data of the win-partition. I tried it with the deep search in test disk

Then I tried with gdisk to repair it, but I can't give him the end sector, it is out of range.

What went wrong. Can you help me?

In this (or any other listed MS Data entry) do you see any familiar files, including 'System Volume Information'?

Hi Loner T,

I went through the entire thread to try and fix my MBR and fix boot camp. But I am stuck now at the end because honestly I don't know what I am looking at and I don't want to destroy the progress that I made. Could you please take a look at my situation and tell me what to do next.

First here is the gpt command you told PhivosZ to exe

I did use test disk to analyze the disk and found the missing MS partition

Now I don't know what to do next and how to fix my situation could you please help me.

Thanks

Good work so far to get to this point. You have found the start/end/size triplet. I have substituted the values from your Testdisk output in the following steps.

You need to use the following steps. If you see any error messages during the following steps, please stop and post back here with the error message. The following steps have values from your Testdisk output (and you can verify) in Steps 7 and 8.

Rebuild GPT4 using start/end offsets

Sudo gdisk /dev/rdisk0

P (print the full list of parts)

D (delete)

4 (part 4)

N (new part)

4 (part 4)

859590656 - Start offset in bytes (start point for Bootcamp part)

+117182457 (Size offset as opposed to End offset)

0700 (Windows part type)

P (print list of all parts just to see what changes will be made)

W (Write the new GPT)

Y (Yes! really write the new GPT)

This will delete and re-write the GPT partition info for /dev/disk0s4.

Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes).

Sudo gdisk /dev/disk0

P (Print list of parts)

R (Recover)

H (chooses Hybrid)

Partitions numbers to be hybridized: 2 3 4

Y (Good for GRUB question)

N (part 2 boot flag)

N (part 3 boot flag)

Y (part 4 boot flag make NTFS bootable partition)

W (Write the new MBR)

Y (Yes! write the new MBR)

Reboot

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you see files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart

If you see a hanging underline cursor at the top left on a black screen, and it does not proceed further, you may need Windows Startup Repair or a tool called EasyBCD.

Thanks Loner,

So now I am at the second execution sequence. Just to be clear I got a question that you did not mention what should I enter for the hex code?

This looks incorrect. Look at the entry #4 on your screen which has a start/end of 898650112/976773119 but what you found from Testdisk was 859590656/976773112. Something did not work correctly in the first set of steps, otherwise you should see the values from Testdisk in entry #4.

Can you post the output of sudo gpt -vv -r show /dev/disk0 as it is now?