After upgrading to Yosemite my external HD is not being recognized. My HD is a WD My Passport 1TB USB 3.0 and I have a MacBook Pro Late 2011

  • It does not show on Finder
  • It does not show on System Information
  • It does not show on Disk Utility (even after using the Debug menu)
  • It does not show on /Volumes

Do you have any ideas why is this happening? Should I reformat my drive?


  • 2
    Please check the cables/correct seating of the connectors/spinning up of the disk first, plug in the drive and then open Terminal and enter diskutil list and add the output to your question
    – klanomath
    Dec 23, 2014 at 11:51

1 Answer 1

  1. Reboot your computer.

  2. Login to your desktop

  3. open up activity monitor.

  4. Check to see if fsck is running

    if fsck is running...

Your computer is attempting to repair the drive, so that is WHY it is not showing up in any of the places you are looking beacuse fsck has already unmounted it.

You have two options (both are risking or dealing with data loss so proceed at your own risk!! )

Option a: You can force quit fsck from activity monitor - then OSX should mount your drive with an error that looks like this...

Finder error / warning

Next steps for option a:

a1. you can attempt to backup and data that you do not have a copy of. Keep in mind the finder might hate copying large files out

a2. If the finder cannot copy files off, you can attempt to repair your file structure or "preview" your drive with disk warrior. To help you copy your files off.

Then assuming option a fails / succeeds and you do not need any data.

Option b:

version 1: If the drive is business critical, then replace it.

version 2: If this drive is for home use and not a huge deal if might die on you randomly then your best bet is to reformat your entire drive and then keeping a eye on it.

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