I had an external hard drive with two partitions (Thing1, Thing2). Thing1 contained manual file backup data and Thing2 was empty and was my targeted drive for Time Machine.

I opened Time Machine and selected Thing2 as the disk for Time Machine to use. Time Machine warned that it was about to format the drive/partition (to which I consented).

I then immediately performed a backup of my Macintosh HD.

After the backup concluded, I noticed that Thing1 was no longer mounted. I rebooted and Thing1 still didn't mount.

When I open Disk Utility, I see the following for my external drive.

Disk Utility Screen Shot

I do not know (cannot recall) what the original partition format of Thing1 was. It would not surprise me if it were a partition format that would be accessible from multiple platforms.

I have not performed any action on the disk (other than inspection) after completing the backup. Thing1 appears to be missing and contains important data that I need to recover. I have spent some time looking for information on what actions Time Machine takes when initializing the drive and for examples of others who have experienced my same mistake. So far no luck so I'm reaching out to your collective knowledge.

It is my hope that the partition table was damaged and that precision actions can make the data accessible again.

I am running macOS Sierra 10.12.3 (16D32).

How can I determine if my original data on Thing1 is recoverable?

  • Please, install TestDisk (it's a command line program) and run it with sudo testdisk. Let it scan the drive and provide a screenshot of the list of possible partitions it shows. – Andrea Lazzarotto Feb 16 '17 at 18:08
  • I'm waiting for a new drive to arrive so that I can make a block copy of the drive in question before using the damage drive. Once the copy has been completed, I'll edit my question to include the requested information. Thank you for your response. – paretech Feb 19 '17 at 17:22
  • Excellent. Making a block copy is indeed the best approach. Nevertheless, if you just let TestDisk scan your drive and then do not go on with the following steps (most importantly the last one called Write) it won't do any harm to the current situation. – Andrea Lazzarotto Feb 19 '17 at 18:28
  • Did you scan the drive with Testdisk? – Andrea Lazzarotto Mar 7 '17 at 21:26
  • Yes, after detailed scan several hundred options returned. I ran through all the options that did not appear to be duplicates and attempted to view the files. No available options were of value to me. I ended up having to result to using photorec and cool myself in my own tears as I wade through the enormous haystack only to find stray fragments of forgotten memories and segments of photoshop layers. Very sad experience but I learned many things. When I feel the need for pain I occasionally revisit and use techniques like md5deep of my other HDs and nsrllookup to reduce the search. Thanks. – paretech Sep 8 '17 at 12:56

You must log in to answer this question.

Browse other questions tagged .