Lost partition after diskpart clean

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Lost partition after diskpart clean

Hi,

While attempting to bootcamp Windows 10 onto a 2010 MBP 6,2 via USB, I was running into issues with the hybrid MBR/GPT tables that Boot Camp Assistant created. I came across some terrible advice that a 'diskpart clean' would aid the issue and it ruined my OSX partition map. I now have a system with no bootable partition and haven't been able to access my OSX partition in any way. I currently have the corrupt system in Target Disk Mode and firewired to another Macbook. I would love to be able to either rewrite the partition table, or recover the data. I am fairly sure all the data is still there.

I've been searching all night through the support forums trying to figure out how to solve this issue, but can't seem to find a proper answer and don't really know how to proceed. I have screen grabs of the typically requested info.

The highlighted partition is almost definitely the one I lost, but pressing 'p' returns "Support for this filesystem hasn't been implemented." I am currently running a deeper scan while I wait just to make sure.

Any advice on how I should proceed?

MacBook Pro (15-inch Mid 2010), OS X El Capitan (10.11.1)

Posted on Nov 29, 2015 6:30 AM

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Answer 1

Best reply

Loner T

Level 9

59,471 points

Nov 29, 2015 12:15 PM in response to jacobchang

Testdisk cannot recover HFS+ or inspect them. You can use GPT Fdisk to recreate the GPT entries, but the content may not be what you expect. Using M$ diskpart utility on a Mac is risky business.

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Answer 2

jacobchang Author

Level 1

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Nov 29, 2015 12:15 PM in response to Loner T

I am currently reading up on gdisk and will give that a try.

At this point I just want the partition to be accessible so I can recover whatever I can. I'm hoping that I can format afterwards without any trouble.

Thank you for the guidance.

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Answer 3

Loner T

Level 9

59,471 points

Nov 29, 2015 1:09 PM in response to jacobchang

Your Testdisk output shows that the HFS+ part ends at 640786567 sectors. The next GPT entry 2 starts at 642779136. Assuming your data is intact, you can try these steps to get GPT1 (OS X) back. If you had CoreStorage AF00 will become AF05.

sudo gdisk /dev/disk1

d

1

n

1

409640

640786567

AF00 (Check this?)

p

w

y

This will not give you the Apple EFI partition (disk0s1) which is not there. To build the EFI, you will need to rebuild the entire GPT. Here is an example of a working disk.

sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=256060514304; sectorsize=512; blocks=500118192

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 500118191

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 250392096 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

250801736 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

252071272 664

252071936 248045568 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

500117504 655

500118159 32 Sec GPT table

500118191 1 Sec GPT header

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