I have 3 external drives connected to an imac:

  1. A 500GB drive which contains my itunes library
  2. A 1TB drive which contains all of my photos and videos
  3. A 2TB time machine drive which backs up the other two external drives and the internal hard drive.

My 500GB external drive (1) failed and will not mount. I am going to buy a replacement, but my question is how do I do the restore? When I go into time machine, I do not see the 500GB drive when I go "back in time". Since the drive is not mounted, it looks like time machine will not recognize the drive in the past. As a test, I disconnected the 1TB drive and it was the same result - I could no longer see the 1TB drive in time machine either. When I plugged the 1TB drive back in, and it shows up in both finder and time machine.

So my question is, when I replace the 500GB drive, how do I get Time Machine to recognize a drive that won't mount so that I can recover the data?. I have read the suggestion to name the volume of the new drive the same as the failed drive, but I have no idea what the failed drive's volume name was.


you don't need to mount the drive to recover the data. using finder or terminal, you should be able to navigate to the location of your backup on (3) and recover the files or directories manually.


Not saying this is the best or only solution, just the way I know to go about doing this.

  1. Connect your Time Machine backup drive.

  2. Go to that drive or Sparse Bundle. You should see a folder named "Backups.backupdb". Open that folder.

  3. You should see a folder with the name of the computer. Open it.

  4. You should see folders with dates as names. Pick the most recent one and open it.

  5. There you should see folders with the computer's name and the names of the external drives that were backed-up.

  6. If you do not see folders there for the external drives then I am afraid they were likely not backed up by Time Machine. You can try some of the other date folders to see if they external drive folders appear in any of them.

  7. Copy the folder(s) for the external drive(s) you want to restore to the new drives in question.

P.S. Avoid using Seagate or Western Digital external drives as they will always fail within 18 to 24 months as you seem to have experienced here.

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