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Upgrade from High Sierra to Mojave corrupted my partition table, unusable MBP.

It's a long post, but I am listing everything I have done so far.

I performed an upgrade to Mojave (day one release from App store), the app installed and I ran through the setup steps, I left it running unattended as it was ‘52 minutes remaining’ I came back to a ‘Disk management error’ (I did not catch the error number at the time), I restarted the machine, and since that point it boots to the Apple logo and the progress bar reaches about ~75% complete before turning into the prohibited symbol.


I have scoured the Apple Support forums and seen some really helpful suggestions from the community, which have led me to the point I am at now, and I’m hoping someone with some greater experience can help, calling out community member LonerT as some posts he has helped others with seem to be part of my issue.


Stupid mistake on my part is not having any backup whatsoever, and the HDD contains family images which is why I’m reluctant to give up and reformat the drive.

I am not too bothered about recovering the whole drive, a satisfactory outcome for me would be the drive is mountable and I can extract the data I want, and from there I don't mind a fresh install.


So here is where I am at, and what I have done:

  • I can load into recovery mode (cmd + r).
  • In disk utility I am only able to see the hardware name of my internal drive (APPLE HDD HT…), in the view menu I ensured ‘Show all devices’ is enabled, still no volume name for which I would expect to see ‘Macintosh HD’.
  • I can see the OS X Base system.
  • At this point I contacted official Apple support (online), once I explained I could see no drive names listed under my internal HDD, they stopped helping and said I would need to reinstall the OS.
  • Tried Target disk mode on another Mac with OSX High Sierra, it could only see the hardware name of my internal drive (APPLE HDD HT…), no volumes.
  • Tried Internet recovery mode, the globe 'spins' then the machine reboots back to into the prohibited symbol.

Output from Recovery mode Disk Utility on the Internal HDD

First Aid found corruption that needs to be repaired.

Checking Core Storage Physical Volume partitions

Problems were found with the partition map, which might prevent booting.

Output from diskutil list


/dev/disk0 (internal, physical):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
GUID_partition_scheme
*500.1 GB
disk0

1:
EFI EFI


209.7 MB
disk0s1

2:
Apple_CoreStorage
499.2 GB

disk0s2

3:
Apple_Boot Recovery HD
650.0 MB disk0s3

/dev/disk1 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
GUID_partition_scheme
+2.1 GB

disk1

1:
Apple_HFS OS X Base System 2.0 GB

disk1s1

/dev/disk2 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+5.2 MB
disk2

/dev/disk3 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB
disk3

/dev/disk4 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB disk4

/dev/disk5 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled +524.3 KB
disk5

/dev/disk6 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+2.1 MB

disk6

/dev/disk7 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB
disk7

/dev/disk8 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB
disk8

/dev/disk9 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+12.6 MB disk9

/dev/disk10 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+4.2 MB disk10

/dev/disk11 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+1.0 MB disk11

/dev/disk12 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+2.1 MB

disk12

/dev/disk13 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB disk13

/dev/disk14 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB
disk14

/dev/disk15 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+1.0 MB

disk15

/dev/disk16 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+6.3 MB

disk16

/dev/disk17 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+6.3 MB disk17

/dev/disk18 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled


+524.3 KB disk18

/dev/disk19 (disk image):

#:
TYPE NAME

SIZE

IDENTIFIER

0:
untitled +2.1 MB
disk19

Output from diskutil cs list

No CoreStorage logical volume groups found

Output from gpt show disk0

-bash-3.2# gpt show disk0

start size index contents

0 1 PMBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 975093952 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

975503592 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

976773128 7

976773135 32 Sec GPT table

976773167 1 Sec GPT header

I booted into Gparted, and what I'm hoping is a positive sign is it can see 'Macintosh HD', but on the flip side a file system of 'unknown' does not fill me with hope. This is where I stopped and thought it's best for someone with better experience to help guide me through any potential data recovery.


User uploaded file

Thank you in advance.

Tools at my disposal:

  • A secondary MBP (same-ish year)
  • Firewire 800 cable
  • External USB with GParted ready to boot
  • External USB blank 150gb HDD

MacBook Pro, macOS High Sierra (10.13.6)

Posted on Sep 30, 2018 9:28 AM

Reply

Similar questions

61 replies

Oct 5, 2018 7:52 PM in response to shannon.young

If SIP is enabled, you will need to disable it, otherwise GPT FDisk will not work.


Once you have SIP disabled, in Terminal , run (do not type text like this)


sudo gdisk /dev/disk0

p (print)

t (change GPT type)

2 (for GPT 2)

af0a (Apple APFS)

p (print)

w (write)

y (confirm write)

q (quit, if necessary)


Once completed, post the output of


diskutil list

Oct 4, 2018 1:36 PM in response to shannon.young

The dd command will dump the first 5 blocks of disk0s2. I want to check what it shows up in the CS header.


The Mojave upgrade could not decide whether to convert the CS to APFS or not, but a HDD CS should not be converted to APFS. Prepare for APFS in macOS High Sierra - Apple Support (before Mojave) clearly states that. Mojave should honor the same rules.

Oct 5, 2018 1:11 PM in response to shannon.young

shannon.young wrote:


Executing fsck_cs (version 546.50.1)

** Checking volume

** disk0s2: Scan for Volume Headers

Invalid Volume Header @ 0: invalid field value

Invalid Volume Header @ 499248102912: unsupported format

** disk0s2 did not complete formatting as a CoreStorage volume

The secondary (working) MBP I am borrowing from work so I can keep hold of for a while, the only critical information/data is family photos which I would like to retrieve, aside from that I don't care much for restoring the whole system. I have no backup whatsoever (in hindsight very very stupid).

Can you post the output of


sudo gpt -vv -r show /dev/disk0


It may help in getting your data back.


shannon.young wrote:



How would I go about installing fresh Mojave onto the external HDD? Is it the same method as creating a bootable live CD?

Download a copy of the Mojave installer from the App Store on your working Mac, connect an external USB Flash drive of 8+ GB, and use How to create a bootable installer for macOS - Apple Support to create a bootable installer. Once you have it, on the troubled Mac, connect the USB flash drive and the second designated Mojave disk, reboot and hold Alt/Option. Select the USB Installer, and once it comes up, select the external Mojave disk. This is critical. You do not want the installer to do anything to the internal disk on the troubled Mac. Once Mojave is installed, we can try and repair the internal disk on the troubled Mac to see if it will repair it to APFS. This will allow you retrieve files, if the conversion from the partially-converted APFS to a 'full' APFS container is possible. After you have your data, we can clean install High Sierra or Mojave on the internal disk of the troubled Mac to get it into a functional state.

Oct 5, 2018 11:12 AM in response to shannon.young

The Mojave upgrade tried to convert the CS to APFS, without taking into account


  • that you have a mechanical HDD, and,
  • if failures do occur, it needs to restore it back to a CS.


Here is an example from my Mac with the APFS header.


sudo dd if=/dev/rdisk2s3 count=5 2>/dev/null | hexdump -C

00000000 36 90 de 83 48 20 5e b6 01 00 00 00 00 00 00 00 |6...H ^.........|

00000010 b2 03 00 00 00 00 00 00 01 00 00 80 00 00 00 00 |................|

00000020 4e 58 53 42 00 10 00 00 31 9d ed 00 00 00 00 00 |NXSB....1.......|

00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000040 02 00 00 00 00 00 00 00 7a 0b 25 be 39 8a 4a d9 |........z.%.9.J.|

00000050 8d d7 67 e3 ab 35 e9 86 17 c9 00 00 00 00 00 00 |..g..5..........|

00000060 b3 03 00 00 00 00 00 00 18 01 00 00 18 6c 00 00 |.............l..|

00000070 0d 67 02 00 00 00 00 00 55 f5 01 00 00 00 00 00 |.g......U.......|

00000080 c1 00 00 00 24 43 00 00 00 00 00 00 00 00 00 00 |....$C..........|

00000090 00 00 00 00 00 00 00 00 08 25 00 00 00 00 00 00 |.........%......|

000000a0 11 ba 03 00 00 00 00 00 01 04 00 00 00 00 00 00 |................|

000000b0 00 00 00 00 64 00 00 00 03 04 00 00 00 00 00 00 |....d...........|

000000c0 06 04 00 00 00 00 00 00 01 25 00 00 00 00 00 00 |.........%......|

000000d0 c6 c3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

*

000003d0 00 00 00 00 00 00 00 00 5b 9f 03 00 00 00 00 00 |........[.......|

000003e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

*

000004f0 00 00 00 00 00 00 00 00 e2 50 39 00 00 00 00 00 |.........P9.....|

00000500 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000510 87 04 76 00 00 00 00 00 01 00 00 00 00 00 00 00 |..v.............|

00000520 01 00 04 00 08 00 00 00 00 00 00 00 00 00 00 00 |................|

00000530 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

*

00000a00


This is a link to someone trying to examine APFS structures - https://blog.cugu.eu/post/apfs/ . This is just informational.


Can you run


sudo fsck_cs -n /dev/rdisk0s2


and post the output? This is non-destructive and tries to look for errors in the CS by looking at other places, where such information may be stored.


How critical is it to get this troubled Mac up an running? Do you have Time Machine backups before the failed Mojave upgrade?

Oct 5, 2018 2:19 PM in response to Loner T

Loner T wrote:


CS is a 'container' for HFS+. If it can be mounted and repaired, it is worth a test. However, all such operations do modify the underlying structures, like the asr adjust of the fsck -fy .

So if i only ran mount -t hfs /dev/disk0s2 /tmpmntpoint

  • What would I use instead of, or could I use /tmpmntpoint, or does it not matter?
  • Is this only a temporary thing, or would it modify something for good?

Oct 5, 2018 6:25 PM in response to shannon.young

At this point we will assume that the macOS version is Mojave on the internal disk, since the fsck_apfs says so.


Can you install GPT FDisk on this Mojave external disk installation? We need to switch the GPT entry to be APFS, not CS. After we switch the GPT to APFS, we need run a repairDisk and ensure it is successful. Then we can


  • look for your files, and,
  • try to boot from the internal disk.

Oct 10, 2018 11:40 AM in response to shannon.young

What we want to do is


  • erase and initialize the whole internal disk of the troubled MAC to Apple HFS+ using the working Mac's Disk Utility
  • install a clean copy of Mojave and verify that it can boot and function normally. Use a login/username that is different from the one you used previously on the trouble Mac
  • If you are satisfied with Mojave, then we can use Time Machine to restore User Settings and applications and files to the newly install Mojave and very that you have all the data
  • also, if you considering an upgrade from the mechanical HDD to an SSD, you should do this first, before we install a clean copy of Mojave

Oct 10, 2018 1:57 PM in response to Loner T

Thanks for your response (and continued help), could I:

  1. Boot the troubled Mac using the external HDD that we clean installed Mojave on and use Disk Utility to erase and initialise the internal drive?
  2. Once erased and initialised, boot from the USB Installer (with Mojave installer app) and select the internal HDD.
  3. Start a fresh account (same login/username), then instead of a restore, transfer the data I want and re-install the Apps I want. Having a clean slate to start from.

Also, aside from having Time Machine backups (which I will from now on), how do you go about installing a major OSX update like Mojave.

Oct 10, 2018 2:30 PM in response to shannon.young

shannon.young wrote:


could I:

  1. Boot the troubled Mac using the external HDD that we clean installed Mojave on and use Disk Utility to erase and initialise the internal drive?
  2. Once erased and initialised, boot from the USB Installer (with Mojave installer app) and select the internal HDD.
  3. Start a fresh account (same login/username), then instead of a restore, transfer the data I want and re-install the Apps I want. Having a clean slate to start from.

Yes, this should work.


shannon.young wrote:


Also, aside from having Time Machine backups (which I will from now on), how do you go about installing a major OSX update like Mojave.

I usually install macOS upgrades


  • first, on a test Mac, which I am willing to wipe clean, without any data loss,
  • second, if you do not have a spare Mac, on an external disk, without touching any internal versions/files
  • third, once the results of the first two are acceptable, upgrade critical Macs to the new version


I still run Mavericks, Yosemite, Sierra (and with some exceptions like Snow Leopard, etc.). I currently have


  • High Sierra on one Mac,
  • Mojave on an external disk


I will not install Mojave on any critical machines, till 10.14.3+. This is typically, a two/three month wait. I also download and preserve each macOS version installer (I have the last PPC version, and all Intel versions).

Sep 30, 2018 10:30 AM in response to shannon.young

Prosoft Data Rescue may be able to recover through a corrupted partition table. You will need a drive larger than the original. http://www.macsales.com/ offers lots of good prices on hard drives. I would only try to use it or Micromat's Techtools Pro.


One thing you have to be really careful of with 10.13 and higher is when installed, it likes to reformat drives into APFS if they are solid state. Having a regular hard drive with a Newertech external drive reader can help immensely.

Oct 4, 2018 11:41 AM in response to shannon.young

I see a reference to Apple HD HT, but can you confirm that your troubled Mac has a mechanical HDD?


Also, in Recovery, if you run


diskutil repairDisk disk0


what does it show in the output?


GPT shows a CS, but cs list not returning a CS indicates a file system conversion failure of sorts. What is the year/model of your Mac (do not post the serial number)?

Oct 4, 2018 11:48 AM in response to Loner T

Hi LonerT, thanks for helping out, much appreciated.


I can confirm, that to the best of my knowledge, the HDD was fully functioning without error before the attempted upgrade, it is the stock HDD (non SSD).


The output of diskutil repairDisk disk0 is:


Repairing the partition map might erase disk0s1, proceed? (y/N)


It's a MacBook Pro (15-inch, Mid 2012).

Upgrade from High Sierra to Mojave corrupted my partition table, unusable MBP.

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