Mac – How to transfer a Time Machine to an NTFS partition (or how to copy HFS+ hard links)

There is a way to make backups like you say, but I don't believe with Robocopy alone.

There are several programs that will hard link or dedupe backups, and be space efficient.

Here are a few programs I've used or ran across:

• Dupemerge - free - While not a "backup program" it is a bulk hard linker.
• hardlink backup - free for personal use - uses hard links
• Duplicati - free - (dedupes I believe like rsync does)
• rdiff-backup - free - dedupes like rsync

I believe what may be a good fit for your questions is Dupemerge. You could have a batch file execute Robocopy to copy the contents to a directory (ex. d:\backups\YYYY-MM-DD). When that command is done, the batch file could call Dupemerge on d:\backups. That would hard link the files within and across all the subdirectories of d:\backups.

The downside of this is you would need enough space on the external to hold the newly created unhard linked backup. After Dupemerge is run, the newly created backup will be hard linked and the space will be freed.

This would make restoring easy because each dated directory would appear to have a full backup.

As a side note, if you are going to use hard links, I like Link Shell Extension. It helps let you know what isn't hard linked, what is and what it is linked to.

I’ve run across other hard link or deduping programs, but I liked these the best.

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.