Boot partition suddenly unusable

Question

I was recently trying to install Ubuntu onto a partition on my Mac (mid 2015 21.5" iMac, running macOS Mojave).A by-product of this was that my macOS boot partition was renamed to FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF rather than Macintosh HD or whatever it was before. It continued working fine before I rebooted my Mac (so I know that all my data is still there) but when I did, there was no way to access the partition.I formatted the 40gb I&#x27;d allocated to Ubuntu and put a fresh install of macOS Sierra on it using recovery mode.I know that my data is formatted as APFS but disk utility doesn&#x27;t recognise it at all.This is what terminal says when I type in diskutil list:/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *1.0 TB     disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF               960.0 GB   disk0s2   3:                  Apple_HFS efwef                   39.3 GB    disk0s3   4:                 Apple_Boot Recovery HD             650.0 MB   disk0s4And this is what it says when I type in diskutil info disk0s2:Device Identifier:        disk0s2   Device Node:              /dev/disk0s2   Whole:                    No   Part of Whole:            disk0   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:    71F124C4-B25D-41F0-88AE-CD4145D652FD   Disk Size:                960.0 GB (960018657280 Bytes) (exactly 1875036440 512-Byte-Units)   Device Block Size:        512 Bytes   Read-Only Media:          No   Read-Only Volume:         Not applicable (no file system)   Device Location:          Internal   Removable Media:          Fixed   Solid State:              NoIt won&#x27;t let me mount it or use any APFS commands because it doesn&#x27;t think it has a file system.I know for sure that disk0s2 is using a file system and that my data is intact, my question is: how do I access it? or, how do I get my Mac to recognise it as what it is?Thank you

r_w_n · Answer

I&#x27;ve made some progress by following whatever guides I could find online, but it still isnt sorted.I now have disk0s2 back, recognised as APFS, but it isnt in a container so my Mac can&#x27;t find a way to use it. It&#x27;s also now 883.2 GB rather than the 960 GB it was before (any explanation for that would be helpful).I dont think I have deleted the files associated with the container, my reason for this is that when I type in diskutil list, after it listing the contents of disk0 and disk1, it shows disk2 to disk17, each with no &#x27;type&#x27; and all called &#x27;untitled&#x27;, each of them being different sizes but none more than 6.3 MB - I think these are the contents of what was previously an APFS container.Prior to this my primary drive was just in a container called &#x27;Container 1&#x27;.I no longer have the ability to paste anything from Terminal here because my fresh install of macOS Sierra diappeared at some point. When I type gpt -r show disk0 theres an entry with no index number that has the size 226802864 (maybe thats the lost partition). there are a couple others but none that size. Any help here would be appreciated.

r_w_n · Answer

I&#x27;ve booted from USB so here&#x27;s what I&#x27;m getting from the terminal.from &#x27;diskutil list&#x27;:/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *1.0 TB     disk0   1:                        EFI EFI                     209.7 MB disk0s1   2:                 Apple_APFS                         883.2 GB disk0s2   3:                 Apple_Boot                         650.0 MB disk0s3/dev/disk1 (external, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *30.8 GB    disk1   1:                        EFI EFI                     209.7 MB disk1s1   2:                  Apple_HFS mac                     29.9 GB    disk1s2   3:                 Apple_Boot Recovery HD             650.0 MB disk1s3and from &#x27;sudo gpt -r show disk0&#x27;:       start        sizeindexcontents           0           1         PMBR           1           1         Pri GPT header           2          32         Pri GPT table          34           6                   40      409600      1GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B      409640 226802864            227212504     1269536      3GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC   2284820401725043095      2GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC1953525135          32         Sec GPT table1953525167           1         Sec GPT header

woodmeister50 · Answer

macOS Sierra has no clue as to how to interpret/read an APFS partition.You need macOS High Sierra or Mojave to read an APFS partition.So, either install High Sierra or Mojave if you want to try to read or fixthe borked partition.

r_w_n · Answer

I&#x27;ve entered sudo dd if&#x3D;/dev/disk0 bs&#x3D;512 count&#x3D;1 skip&#x3D;409640 | hexdump -Cv and this is the result:

r_w_n · Answer

I&#x27;m about to install Mojave to read the APFS disk, but until then these are the files that iBoysoft Data Recover has found, in case anything useful can be gleaned from this:

r_w_n · Answer

I&#x27;ve installed mojave on a usb, it&#x27;s running fine. What steps should I take next?

Boot partition suddenly unusable

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