Recently my Macbook's hard disk started to get badblocks and I promptly managed to make a disk clone with ddrescue into an external drive through an Ubuntu live session. I successfully cloned everything without much issues.
When I plug this external drive using Ubuntu I can access all partitions. But unfortunately when I try to access this drive on macOS itself the Apple_CoreStorage partition doesn't mount.
Here's my diskutil list output:
paulofreitas@Paulos-MacBook-Pro:~$ 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 Macintosh HD 499.2 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
/dev/disk1 (internal, virtual):
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS Macintosh HD +498.9 GB disk1
Logical Volume on disk0s2
F0CA4975-A73D-46D6-92AB-4A4DDF3DFFF7
Unencrypted
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *2.0 TB disk2
1: Apple_HFS Storage 2.0 TB disk2s1
/dev/disk3 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *2.0 TB disk3
1: EFI EFI 209.7 MB disk3s1
2: Apple_CoreStorage 499.2 GB disk3s2
3: Apple_Boot Recovery HD 650.0 MB disk3s3
4: Apple_HFS Time Machine 1.5 TB disk3s4
The external hard drive is the /dev/disk3. The first 3 partitions are an exact copy of /dev/disk0 at the time I did the clone. The last partition Time Machine was later created with the free disk space that was left.
I can't mount /dev/disk3s2 inside macOS although I can do that when using Ubuntu. Am I missing something? What should I do to mount this partition?
Update
From what I've understood the problem happens because both /dev/disk0s2 + /dev/disk3s2 and /dev/disk0s3 + /dev/disk3s3 shares the same disk label. My /Volumes/Macintosh HD lists the Macbook filesystem itself, ie. it's the /dev/disk1 (from /dev/disk0s2).
Actually this happens because both disk GPT GUID and partitions GPT GUIDs share the same UUIDs. I still haven't found a way or tool to change those partitions GUIDs safely (where I can mount them without compromising their data).
Best Answer
I have tested your set-up in a virtual machine with the same result - the second CoreStorage volume won't be mounted. Cloning a CoreStorage container to another disk with dd doesn't change the UUIDs of the CoreStorage items. So it's indeed a problem of the duplicate UUIDs of the Logical Volume Group/Physical Volume/Logical Volume Family/Logical Volume of disk0s2 and disk3s2.
The good news is: there is a man entry for a tool which can change the UUIDs of all CoreStorage metadata objects:
man csunique.Check the disk identifier of the duplicate with
diskutil list. In your example that's disk3s2.Then the command in your case would be:
The bad news is: I can't find the tool/script. It's neither in the path nor can I find a file with this name elsewhere on the disk. I checked this in 10.9/10.10/10.11/Recovery HD by searching the whole disk even inside packages with FileBuddy. A Google search wasn't successful.
Work in progress
You may change the various UUIDs manually by editing the raw disk content with a tool like HexEdit or wxHexEditor of course. AFAIR the pvUUID and the lvgUUID are located at the first block of disk3s2. The pvUUID/lvgUUID has several additional occurrences in the metadata area of the Logical Volume Group of disk3s2. Don't use arbitrary (ie self-made) UUIDs but try to generate them with
uuidgenor online with a UUID generator. Some bits of the UUID have a special meaning and determine UUID version or the hash algorithm.Example:
The diskutil cs list output of the original disk:
The pvUUID (light violet) and lvgUUID (light yellow) appear in hex in the first block and the last block of the partition:
1st block:
last block:
and as text each four times in the last 32760 blocks (512 byte physical block size) of the partition in plist-like items.