corrupted partition table, need help fixing

Hello (Loner T),


I have an issue with my partition table and need to rebuild it. Would you please assist ?


Output of: 


sudo gdisk /dev/disk0




GPT fdisk (gdisk) version 1.0.4




Warning: Devices opened with shared lock will not have their


partition table automatically reloaded!


Partition table scan:


  MBR: protective


  BSD: not present


  APM: not present


  GPT: present




Found valid GPT with protective MBR; using GPT.




Command (? for help): P




Disk /dev/disk0: 490234752 sectors, 233.8 GiB


Sector size (logical): 512 bytes


Disk identifier (GUID): 57ECCA5D-3ED3-4ECC-B8F8-568B5DF9C6D0


Partition table holds up to 128 entries


Main partition table begins at sector 2 and ends at sector 33


First usable sector is 34, last usable sector is 490234718


Partitions will be aligned on 8-sector boundaries


Total free space is 4035 sectors (2.0 MiB)




Number  Start (sector)    End (sector)  Size       Code  Name


   1             40          409639   200.0 MiB   EF00  EFI System Partition


   2         409640       195858431   93.2 GiB    AF0A  


   3      195858432       469830561   130.6 GiB   0700  Basic data partition


   4       469831680       470835199   490.0 MiB   2700  


   5       470837248       490233855   9.2 GiB     AF00  Apple HFS/HFS+






Output of:


sudo gpt -r show /dev/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  195448792 2  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC


195858432  273972130 3  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7


469830562       1118         


469831680    1003520      4  GPT part - DE94BBA4-06D1-4D40-A16A-BFD50179D6AC


470835200       2048         


470837248   19396608     5  GPT part - 48465300-0000-11AA-AA11-00306543ECAC


490233856        863         


490234719         32         Sec GPT table


490234751          1         Sec GPT header

MacBook Pro Retina

Posted on Aug 26, 2019 9:01 PM

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49 replies

Aug 27, 2019 3:38 PM in response to Loner T

Hello LonerT,


sorry for the delay with replying ....


The RE partition sneaked itself in with the Windows 10 April update. Didn't notice it because it's hidden by default.


The HFS+ partition is my share space between Windows/macOS. I don't recall how I created it initially (either with du, or with Paragon HDM). But yesterday I did use HDM (against your past advice on the subject), to merge some space that HDM was showing as unused/unallocated (something around 130MB) with the HFS+ partition. Unfortunately HDM screwed up the partition table again.


here is the output you requested:


diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk1 100.1 GB disk0s2

3: Microsoft Basic Data Windows 140.3 GB disk0s3

4: Windows Recovery 513.8 MB disk0s4

5: Apple_HFS SHARE 9.9 GB disk0s5


/dev/disk1 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +100.1 GB disk1

Physical Store disk0s2

1: APFS Volume macOS - Data 38.2 GB disk1s1

2: APFS Volume Preboot 79.5 MB disk1s2

3: APFS Volume Recovery 528.6 MB disk1s3

4: APFS Volume VM 1.1 GB disk1s4

5: APFS Volume macOS 10.3 GB disk1s5


Aug 28, 2019 4:17 PM in response to Loner T

output of sudo fdisk /dev/disk0:


Disk: /dev/disk0   geometry: 30515/255/63 [490234752 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 -  490234751] <Unknown ID>
 2: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

Aug 30, 2019 7:13 PM in response to Loner T

both OS's boot normally


In Windows, File Explorer, the SHARE partition is no longer shown, whereas before the restructuring, it was present and browsable. I have an HFS driver in Windows that allows me to read/write on HFS/HFS+ partitions.


I had a look at Disk Management in Windows while I was booted in, this is what I saw:



do not know if that unallocated space of 128MB is of any concern ... ?

Aug 30, 2019 8:09 PM in response to Loner T

ah yes, the drive letter was unassigned. went into Disk Management, assigned a letter and now it appears in File Explorer. Thanks for mentioning that.


before moving on, wanted to show you these errors from DU. Only "Container disk 1" and "macOS - Data" are showing fsroot tree errors. the errors have been around dating back to High Sierra days. would be beneficial for you to know I'm on the next macOS version beyond Mojave.




for reasons that escape me, i cannot find the reason or source of the errors and have been unsuccessful with fixing.


i suppose that if it doesn't impact the APFS partition integrity or fixing the GPT, i'll ignore these errors.

Aug 31, 2019 9:47 PM in response to Loner T

/dev/disk1s5 on / (apfs, local, read-only, journaled)
devfs on /dev (devfs, local, nobrowse)
/dev/disk1s1 on /System/Volumes/Data (apfs, local, journaled, nobrowse)
/dev/disk1s4 on /private/var/vm (apfs, local, journaled, nobrowse)
/dev/disk0s3 on /Volumes/Windows (ntfs, local, read-only, noowners)
/dev/disk0s4 on /Volumes/SHARE (hfs, local, journaled)
map auto_home on /System/Volumes/Data/home (autofs, automounted, nobrowse)
//admin@wdmycloud/Public on /Volumes/Public (smbfs, nodev, nosuid, mounted by *****)
//*****@wdmycloud/***** on /Volumes/***** (smbfs, nodev, nosuid, mounted by *****)
//admin@wdmycloud/My_Book on /Volumes/My_Book (smbfs, nodev, nosuid, mounted by *****)

Sep 1, 2019 8:14 AM in response to Loner T

i was able to merge the unallocated 128mb of space with the SHARE partition, and went back to gdisk to do a verify.


results say there are no problems with the GPT. aside from 3 segments of unallocated space totaling about 900kB, it seems the table is in good shape.


since my partitions are functional, working well ... i dont think theres a need to focus on the GPT anymore.


but it would be nice to try to fix the fsroot tree errors i have, if they are fixable.


concerning unmounting disk1, looks like disk1 contains the parts of macOS that im booted into. how would i unmount it ?

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corrupted partition table, need help fixing

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