Partition type suddenly FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF, drive unmountable

disk-utilityfilesystemfilevaulthard drivepartition

I have two drives inside my MBP, an SSD for the OS and the original HDD for large Data. The HDD has 3 Partitions:

My Data (Core Storage volume)
20Gb for Linux
4Gb for Linux Swap

Recently I ran repair disk on the drive, as Disk Utility thought it was damaged. The repair aborted with the request to format and restore the whole drive, but I could use it like before (so maybe unrelated). Last night, everything was normal, but when I woke up, my data partition looked like this:

It used to be named Macintosh HD (like the drive) and now it has lost its name and the partition type turned into FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF.
diskutil info /dev/disk1s2 reports

   Device Identifier:        disk1s2
   Device Node:              /dev/disk1s2
   Part of Whole:            disk1
   Device / Media Name:      Macintosh HD

   Volume Name:              Not applicable (no file system)

   Mounted:                  Not applicable (no file system)

   File System:              None

   Partition Type:           FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF
   OS Can Be Installed:      No
   Media Type:               Generic
   Protocol:                 SATA
   SMART Status:             Verified
   Disk / Partition UUID:    00002980-188B-0000-A938-00003F710000

   Total Size:               475.0 GB (474999996416 Bytes) (exactly 927734368 512-Byte-Units)
   Volume Free Space:        Not applicable (no file system)
   Device Block Size:        512 Bytes

   Read-Only Media:          No
   Read-Only Volume:         Not applicable (no file system)
   Ejectable:                No

   Whole:                    No
   Internal:                 Yes
   Solid State:              No

Also a partition named Boot OS X seems to be constantly mounted, even after restart, which has not been the case before.
Now, I have most of the data backed up, but can I somehow get my partition back without all the hassle?

Edit:

$ sudo gpt -r show /dev/disk1
gpt show: /dev/disk1: Suspicious MBR at sector 0
      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  927734368      2  GPT part - FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF
  928144008     262144      3  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  928406152     615800
  929021952   39294976      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  968316928       2048
  968318976    8388608      5  GPT part - 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F
  976707584      65551
  976773135         32         Sec GPT table
  976773167          1         Sec GPT header


$ sudo fdisk /dev/disk1
Disk: /dev/disk1    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: DA 1023 254  63 - 1023 254  63 [    409640 -  927734368] <Unknown ID>
 3: AF 1023 254  63 - 1023 254  63 [ 928144008 -     262144] HFS+
 4: 83 1023 254  63 - 1023 254  63 [ 929021952 -   39294976] Linux files*

Since I know that it was an OSX Journaled file system in a Core Storage Volume, can I somehow convince OSX of this fact and fix the partition? Do I maybe need to edit the partition table?

As suggested, I removed partitions 2 and 3 with

sudo gpt remove -i 3 /dev/disk1
diskutil umountDisk /dev/disk1
sudo gpt remove -i 2 /dev/disk1

Now the partition table is

$ sudo gpt -r show /dev/disk1
gpt show: /dev/disk1: Suspicious MBR at sector 0
      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  927734368      2  MBR part 218
  928144008     262144      3  MBR part 175
  928406152     615800
  929021952   39294976      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  968316928       2048
  968318976    8388608      5  GPT part - 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F
  976707584      65551
  976773135         32         Sec GPT table
  976773167          1         Sec GPT header

Best Answer

You have to edit the partition table and modify the type of disk1s2 (and correct the type of disk1s3) to get your main data partition back and make Boot OS X invisible:

Log-in as admin
Open Terminal and enter
```
sudo gpt -r show /dev/disk1
```
to get an overview
Unmount disk1:
```
diskutil umountDisk /dev/disk1
```

Remove partition 2 and 3:

sudo gpt remove -i 3 /dev/disk1
diskutil umountDisk /dev/disk1
sudo gpt remove -i 2 /dev/disk1

Re-add the partition 2 and 3

diskutil umountDisk /dev/disk1
sudo gpt add -b 928144008 -i 3 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk1
diskutil umountDisk /dev/disk1
sudo gpt add -b 409640 -i 2 -s 927734368 -t 53746F72-6167-11AA-AA11-00306543ECAC /dev/disk1

The correct partition type of a Boot OS X partition is 426F6F74-0000-11AA-AA11-00306543ECAC (like a Recovery HD partition) and 53746F72-6167-11AA-AA11-00306543ECAC for a CoreStorage partition.

Update: gpt behaves strange because the partition table contains an MBR instead of an PMBR - the MBR has to be replaced by a PMBR:

Reboot your Mac
Open Terminal and enter
```
sudo gpt -r show /dev/disk1
```
to get an overview and all partition sizes/types

rebuilding the GUID partition table and destroying the bogus MBR

diskutil umountDisk /dev/disk1
sudo gpt destroy /dev/disk1
diskutil umountDisk /dev/disk1
sudo gpt create -f /dev/disk1
sudo gpt add -b 40 -i 1 -s 409600 -t C12A7328-F81F-11D2-BA4B-00A0C93EC93B /dev/disk1
sudo gpt add -b 409640 -i 2 -s 927734368 -t 53746F72-6167-11AA-AA11-00306543ECAC /dev/disk1       
diskutil umountDisk /dev/disk2 
diskutil umountDisk /dev/disk1
sudo gpt add -b 928144008 -i 3 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk1
diskutil umountDisk /dev/disk2
diskutil umountDisk /dev/disk1
sudo gpt add -b 929021952 -i 4 -s 39294976 -t EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 /dev/disk1
diskutil umountDisk /dev/disk2
diskutil umountDisk /dev/disk1
sudo gpt add -b 968318976 -i 5 -s 8388608 -t 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F /dev/disk1

Related Solutions

I think I messed up the Fusion Drive on the 1TB iMac (with BootCamp)

Theoretically everything is fine with your Fusion Drive. Fusion Drives look like this. Disk0 is your SSD with 121 GB and disk1 is your HDD with ~1 TB (~1.121 TB summed up).

The larger parts of your SSD (disk0s2) and your HDD (disk1s2) are pooled to a CoreStorage LVG (Fusion Drive: disk3) with a size of 967.8 GB. The rest is reserved for EFIs, a Recovery HD (alltogether ~1.3 GB) and your old Windows partition - now probably free space (~152 GB).

The logical volume 'Macintosh HD' (967.8 GB) spans disk0s2 and disk1s2. This is the first 'Macintosh HD' in picture 1. The volume 'Macintosh HD' - it's the one visible on the desktop - should ideally also have about 967.8 GB. This is the second 'Macintosh HD' in picture 1.
In fact it has only 852.67 GB (see picture 3).

In the second picture the logical volume 'Macintosh HD' is the first listed in black, the volume 'Macintosh HD' is the second listed in black, the other two 'Macintosh HD's listed in grey are the parts of your SSD and HDD dedicated to the logical volume 'Macintosh HD'.

In my opinion something went wrong after deleting various partitions with the Bootcamp Assistant/Disk Utility or in Windows.

Preparation:

Detach any external drive (especially your external Time Machine backup drive)
Restart to Internet Recovery Mode by pressing alt cmd R at startup.
The prerequisites are the latest firmware update installed, either ethernet or WLAN (WPA/WPA2) and a router with DHCP activated.
On a 50 Mbps-line it takes about 4 min (presenting a small animated globe) to boot into a recovery netboot image which usually is loaded from an apple/akamai server.

I recommend ethernet because it's more reliable. If you are restricted to WIFI and the boot process fails, just restart your Mac until you succeed booting.

Alternatively you may start from a bootable installer thumb drive (preferably Mavericks or Yosemite) or a thumb drive containing a full system (preferably Mavericks or Yosemite).

Now you may either repair CoreStorage or rebuild your Fusion Drive:

'Repair CoreStorage' (not recommended):

First i would try to check the volume 'Macintosh HD' with Disk Utility. If the volume is corrupted consider a reinstall of Mac OS X.
If the volume is ok quit Disk Utility
Open Terminal and enter diskutil unmountDisk /dev/LVIdentifier and both diskutil unmountDisk /dev/DiskContainingApple_CoreStorageIdentifier
In your case: first diskutil unmountDisk /dev/disk3 then diskutil unmountDisk /dev/disk0 and diskutil unmountDisk /dev/disk1
remove the EFI NO NAME partition with gpt remove -i IndexNumberOfEFINoName DiskIdentifier:
gpt remove -i 4 disk1
Remount the CoreStorage disks and then the Logical Volume:
In your case: first diskutil mountDisk /dev/disk0 and diskutil mountDisk /dev/disk1 and then diskutil mount /dev/disk3.

enter gpt -r -vvv show /dev/diskIdentfierOfApple_CoreStorage to get infos of your HDD CoreStorage disk.
In your case: gpt -r -vvv show /dev/disk1
It should look like this:

-bash-3.2# gpt -r -vvv show /dev/disk1
gpt show: /dev/disk1: mediasize=1000204886016; sectorsize=512;         blocks=1953525168
gpt show: /dev/disk1: PMBR at sector 0
gpt show: /dev/disk1: Pri GPT at sector 1
gpt show: /dev/disk1: GPT partition: type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, start=40, size=409600
gpt show: /dev/disk1: GPT partition: type=53746F72-6167-11AA-AA11-00306543ECAC, start=409640, size=1671210848
gpt show: /dev/disk1: GPT partition: type=426F6F74-0000-11AA-AA11-00306543ECAC, start=1671620488, size=1269760
gpt show: /dev/disk1: Sec GPT at sector 1953525167                               
     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    1671210848      2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
1671620488       1269760      3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1672890248     280634887
1953525135            32        Sec GPT table
1953525167             1        Sec GPT header

The free space on your HDD has 280634887 blocks. Please calculate the biggest block number dividable through 8. That's 280634880 blocks (á 512 bytes) which equals 143685058560 B or ~143.7 GB. Add the size of your HDD CoreStorage Physical Volume (852666400768 B) The result is 143685058560 B + 852666400768 B = 996351459328 B
Resize your HDD CoreStorage physical volume with diskutil cs resizeDisk HDDPVUUID newsize
In your case: diskutil cs resizeDisk 93892BE8-2B7F-4ABD-A4C3-984495DCD98D 996351459328b
Calculate the maximal size of your CoreStorage Logical Volume in diskutil cs list: (size disk0s2) + (size disk1s2) In your case that's 120988852224 B + 996351459328 B = 1117340311552 B. That should be the size of your refreshed Logical Volume Group.
Resize your Logical Volume with diskutil cs resizeVolume LVUUID LVGSize-128 MB In your case that's diskutil cs resizeVolume D237FFDC-7DA4-41D7-AC13-4CC7E5E8C0A0 1117212311552b. If you get an error (There is not enough free space...) choose a smaller size like 1117148311552b.
Quit Terminal and open Disk Utility.
Check your expanded CoreStorage Volume for errors.
Quit Disk Utility, choose your CS volume as startup disk and restart your Mac

'Rebuild Fusion Drive' (recommended if you have a Time Machine backup)

Booted to Internet Recovery Mode open Utilities → Terminal in the menubar and enter:
diskutil cs list to get the CoreStorage listing.
Copy the Logical Volume UUID, it's the fifth listed.
Now delete the Logical Volume with diskutil cs deleteVolume LVUUID.
In your case: diskutil cs deleteVolume D237FFDC-7DA4-41D7-AC13-4CC7E5E8C0A0.
Copy the Logical Volume Group UUID, it's the first listed in the listing of diskutil cs list.
Then delete the Logical Volume Group with diskutil cs delete LVGUUID.
In your case: diskutil cs delete 1EFE58BC-3613-44C4-86EE-D816F3B66E3E
Enter exit and quit 'Terminal'
Open 'Disk Utility'. Enter 'Ignore' if you are asked to fix the drives.
Choose your SSD and partition it: 1 Partition Mac OS X Extended (Journaled), hit the Options button and choose GUID Partiton table and hit OK and Apply.
Please check that the size is ~121 GB

Example:
Choose your HDD and partition it: 1 Partition Mac OS X Extended (Journaled), hit the Options button and choose GUID Partiton table and hit OK and Apply.
Please check that the size is ~1 TB

Example:
Quit Disk Utility and open Terminal
Enter diskutil list

Example (your disk identifiers and sizes are different of course: Your volume SSD probably has the Identifier disk0s2 and the size 121 GB and your volume HDD probably has the Identifier disk1s2 and the size 1.0 TB):
Enter diskutil cs create "Name" IdentifierSSD IdentifierHDD
In your case probably diskutil cs create "Macintosh HD" disk0s2 disk1s2.

Copy the resulting LVGUUID

Example:
Enter diskutil cs CreateVolume LVGUUID jhfs+ "Macintosh HD" 100%.

Example:
Enter diskutil cs list
Check the size of your Logical Volume. It should have the size ~1.121 TB

Example:
Quit Terminal
Open 'Disk Utility' and check your newly created volume for errors
Quit 'Disk Utility'
Attach your external Time Machine backup drive or check this answer if you use NAS or another network share.
Open 'Restore from Time Machine Backup'
Choose the appropriate Time Machine backup and restore your system
Reboot to your restored system.
Unmount and detach your Time Machine backup drive
Open 'Terminal' and enter 'diskutil list'
Check if your 'Recovery HD' is listed.
If your 'Recovery HD' is missing, usually reinstalling your current system with the latest available system installer (e.g. 'Install OS X Mavericks (10.9.5)' if Mavericks is currently installed) will recreate it without loosing any data. AFAIK Recovery Partition Creator 3.8 will NOT create a Recovery HD on CoreStorage volumes.
After reinstalling the system with the latest available system installer open App Store and install the latest security fixes.

Drive unmountable FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF issue

The partition disk2s5 has the wrong partition type. It should be 53746F72-6167-11AA-AA11-00306543ECAC instead of FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF!

To solve this boot to Macintosh HD (disk0s2/disk1), open Terminal and enter:

to get an overview:
```
diskutil list
```
below I assume the external disk has the disk identifier disk2
```
sudo gpt -r show /dev/disk2
```
unmount disk2:
```
diskutil umountDisk /dev/disk2
```
remove the partition entry with the index 5 (and the type FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF):
```
sudo gpt remove -i 5 /dev/disk2
```

re-add the same partition entry but with the proper type:

diskutil umountDisk /dev/disk2
sudo gpt add -i 5 -b 781921784 -s 976562504 -t 53746F72-6167-11AA-AA11-00306543ECAC /dev/disk2

the external file vault volume (disk2s5) should be mounted automatically and you will be asked for the password. If not, enter diskutil cs list and diskutil cs unlockVolume lvUUID (with lvUUID: the Logical Volume UUID inside the second Logical Volume Group)

Update because the Recovery HD partition was removed somehow:

Remove all partitions:

diskutil umountDisk /dev/disk2
sudo gpt destroy /dev/disk2
diskutil umountDisk /dev/disk2
sudo gpt create -f /dev/disk2

re-add all partitions one by one:

sudo gpt add -i 1 -b 40 -s 409600 -t C12A7328-F81F-11D2-BA4B-00A0C93EC93B /dev/disk2
sudo gpt add -i 3 -b 780390104 -s 1269536 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk2
sudo gpt add -i 4 -b 781659640 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk2
sudo gpt add -i 6 -b 1758484288 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk2
sudo gpt add -i 8 -b 3631786896 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk2
sudo gpt add -i 10 -b 3906701272 -s 262144 -t 426F6F74-0000-11AA-AA11-00306543ECAC /dev/disk2
sudo gpt add -i 2 -b 409640 -s 779980464 -t 48465300-0000-11AA-AA11-00306543ECAC /dev/disk2
diskutil umountDisk /dev/disk2
sudo gpt add -i 7 -b 1758746432 -s 1873040464 -t 48465300-0000-11AA-AA11-00306543ECAC /dev/disk2
diskutil umountDisk /dev/disk2
sudo gpt add -i 9 -b 3632049040 -s 274652232 -t 48465300-0000-11AA-AA11-00306543ECAC /dev/disk2
diskutil umountDisk /dev/disk2
sudo gpt add -i 5 -b 781921784 -s 976562504 -t 53746F72-6167-11AA-AA11-00306543ECAC /dev/disk2

I have chosen a "non-sequential" adding of partitions to unmount disk2 less often!

Best Answer

Related Solutions

I think I messed up the Fusion Drive on the 1TB iMac (with BootCamp)

Drive unmountable FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF issue

Related Question