Macos – How to create HFS+ partition on Windows 7 machine

Can GParted rewrite the partition map (delete the linux partition and then resize the remaining HFS+ partition) without trying to enlarge the HFS+ filesystem? If so you might then be able to use diskutil to enlarge the HFS+ filesystem to fit the bounds of the newly grown partition.

Before trying this (or even using any of the commercial software), you should make sure you have a full backup (that way you can just destructively redo the partition with Disk Utility and restore from your backup—plus get a ‘free’ defrag for your troubles).

I tried various other search terms and found that this question is actually a duplicate of this one: OS X 10.6 Snow Leopard no longer mounting an external USB drive.

Here's what I did to fix:

1. Download and install GPT fdisk

2. Run gdisk and select problem drive:

   ~% sudo gdisk
   GPT fdisk (gdisk) version 0.8.1
   
   Type device filename, or press <Enter> to exit: /dev/disk3
   Partition table scan:
     MBR: protective
     BSD: not present
     APM: not present
     GPT: present
   
   Found valid GPT with protective MBR; using GPT.
   

3. Look at the partitions using the p command:

   Command (? for help): p
   Disk /dev/disk3: 1953525168 sectors, 931.5 GiB
   Logical sector size: 512 bytes
   Disk identifier (GUID): ABFA9105-73F4-4627-9890-9DECC55E86AC
   Partition table holds up to 128 entries
   First usable sector is 34, last usable sector is 1953525134
   Partitions will be aligned on 8-sector boundaries
   Total free space is 3389 sectors (1.7 MiB)
   
   Number  Start (sector)    End (sector)  Size       Code  Name
      1              40          409639   200.0 MiB   EF00  EFI System Partition
      2          409640      1367597143   651.9 GiB   0700  Time Machine Backups
      3      1367599104      1953523711   279.4 GiB   0700  Basic data partition
   

   In this case, it's partition 2 that's causing the problem. And the problem is that its type code is 0700, which means something other than HFS.

4. Use the t command to set the partition type to af00 - Apple HFS/HFS+.

   Command (? for help): t
   Partition number (1-3): 2
   Current type is 'Microsoft basic data'
   Hex code or GUID (L to show codes, Enter = af00): 
   Changed type of partition to 'Apple HFS/HFS+'
   

5. Use the w command to write the stuff back to disk and quit.

   Command (? for help): w
   
   Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
   PARTITIONS!!
   
   Do you want to proceed? (Y/N): y
   OK; writing new GUID partition table (GPT).
   Warning: The kernel may continue to use old or deleted partitions.
   You should reboot or remove the drive.
   The operation has completed successfully.
   

The HFS+ partition, and all of its contents, then became visible again to OS X.