Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.


I'm fixing my fiends USB drive. AFIK it was inserted into Windows, and partition were corrupted.

I did manage to fix GUID headers with gpt_surgeon.py and mount it, but then mac did got messy, slow, sth like filesystem write errors occured.. (partition may be corrupted now)

The problem is: I see now 2 out of 3 partitions.

I do have a copy of my gpt header done before on my Ubuntu :) , I did restore it with gdisk, but eventhough I can see partitons, mac (diskutil) still sees only 2 of them


sh-3.2# diskutil list /dev/disk1
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *2.7 Ti     disk1
  1:                  Apple_HFS                         128.0 Mi   disk1s1
  2:                  Apple_HFS                         2.7 Ti     disk1s2

sh-3.2#  gpt -r -vv show disk1
gpt show: disk1: mediasize=3000592981504; sectorsize=512; blocks=5860533167
gpt show: disk1: PMBR at sector 0
gpt show: disk1: Pri GPT at sector 1
gpt show: disk1: Sec GPT at sector 5860533166
      start        size  index  contents
          0           1              PMBR
          1           1              Pri GPT header
          2          32              Pri GPT table
         34      262144      1  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE
     262178           6         
     262184      409600      2  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     671784        2008         
     673792  5859597192      3  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
5860270984      262150         
5860533134          32              Sec GPT table
5860533166           1              Sec GPT header


parted /dev/sdc print
Model: WDC WD30 EZRX-00MMMB0 (scsi)
Disk /dev/sdc: 3001GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name                          Flags
 1      17.4kB  134MB   134MB                Microsoft reserved partition  msftres
 2      134MB   344MB   210MB   fat32        EFI System Partition          boot
 3      345MB   3000GB  3000GB  

and gdisk: root@ # gdisk /dev/sdc GPT fdisk (gdisk) version 0.8.5

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): r

Recovery/transformation command (? for help): l
Enter backup filename to load: 3tbgpt.backup

Recovery/transformation command (? for help): i
Partition number (1-3): 1
Partition GUID code: E3C9E316-0B5C-4DB8-817D-F92DF00215AE (Microsoft reserved)
Partition unique GUID: 4100C4FF-AB62-4A9E-BD57-3FF3DBA219F0
First sector: 34 (at 17.0 KiB)
Last sector: 262177 (at 128.0 MiB)
Partition size: 262144 sectors (128.0 MiB)
Attribute flags: 0000000000000000
Partition name: 'Microsoft reserved partition'

Recovery/transformation command (? for help): i
Partition number (1-3): 2
Partition GUID code: C12A7328-F81F-11D2-BA4B-00A0C93EC93B (EFI System)
Partition unique GUID: 42A4C1CA-1038-4ABA-BFBA-3FCEA700617C
First sector: 262184 (at 128.0 MiB)
Last sector: 671783 (at 328.0 MiB)
Partition size: 409600 sectors (200.0 MiB)
Attribute flags: 0000000000000000
Partition name: 'EFI System Partition'

Recovery/transformation command (? for help): i
Partition number (1-3): 3
Partition GUID code: 48465300-0000-11AA-AA11-00306543ECAC (Apple HFS/HFS+)
Partition unique GUID: 8F70AEB5-6572-484C-948B-1BEE834630A9
First sector: 673792 (at 329.0 MiB)
Last sector: 5860270983 (at 2.7 TiB)
Partition size: 5859597192 sectors (2.7 TiB)
Attribute flags: 0000000000000000
Partition name: 'Apple_HFS_Untitled_2'


fsck.hfsplus /dev/sdc3
** /dev/sdc3

fsck not working :/

I would already give up, But the fact that I did manage to make it work makes me try harder. I think mac might have do sth to the partition table while it failed unmounting

I tried with hybrid mbr and conversion gpt to mbr - at this step I had only 2 partitions, while before there were 3 on gpt

Number  Start   End    Size   Type     File system  Flags
 1      17.4kB  134MB  134MB  primary               lba
 2      134MB   344MB  210MB  primary  fat32
 (3 is missing while gpt-> mbr conversion)
share|improve this question

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.