wire nut

Q: Encrypted Time Machine Volume won't Unlock

After encrypting a Time Machine backup, I can no longer access it.

 

It was an existing backup, not a new one, and it had other important files as well. It was encrypted with the checkbox in the TM preferences pane, not FileVault or any other means. When I plug in the drive (1TB Seagate Barracuda 7200.12) via USB, the window to unlock it pops up, but it always denies my attempts as if my passcode is incorrect. I'm 98% certain that my password is correct, and I've tried all other possibles passwords.

 

I'm unconcerned about losing the backups, but it's my other files on the drive that I can't afford to lose.

 

Running a Thorough Scan with Prosoft's Data Rescue reveals a lot of plists and keys that allude to the TM encryption, but opening them in TextEdit reveals a blank document, even after unlocking them with the admin pass.

 

I wonder if there's a way to find the key in the aforementioned files I recovered that could lead to a way to unlock the encryption?

 

I'm tempted to reformat the drive and just recover my important files once unlocked, but will the encryption render the recovery useless?

MacBook Pro with Retina display, OS X Mountain Lion (10.8.3)

Posted on Apr 29, 2013 6:15 AM

Close

Q: Encrypted Time Machine Volume won't Unlock

  • All replies
  • Helpful answers

  • by Topher Kessler,

    Topher Kessler Topher Kessler Apr 29, 2013 8:12 AM in response to wire nut
    Level 6 (9,866 points)
    Apr 29, 2013 8:12 AM in response to wire nut

    Without the password or the encryption key the drive's contents will be irrecoverable. You might try bypassing the graphic user interface to see if the drive can be mounted using the Terminal. To do this, open the Terminal and run the following command:

     

    diskutil cs list

     

    In the output, which should look like a hierarchical tree, note the UUID string of the "Logical Volume" (this string will be a number of letters and numbers, separated by dashes).

     

    Highlight this number and copy it, and the run the following command, replacing UUID with the copied UUID from the last command, and replacing PASSWORD with your password:

     

    diskutil cs unlockVolume UUID -passphrase PASSWORD

     

    If you make a mistake and want to try another password, simply press the up-arrow and the previous entered command will be available for you to edit and re-execute.

     

    If you have any troubles or need further guidance, copy the output of these commands to additional messages here so we can have a closer look at the drive setup. However, if ultimately the drive is corrupt or otherwise not accepting the passwords you know, then being encrypted its contents will essentially be lost.

  • by wire nut,

    wire nut wire nut Apr 29, 2013 8:48 AM in response to Topher Kessler
    Level 1 (15 points)
    Apr 29, 2013 8:48 AM in response to Topher Kessler

    Thanks for the instructions. This is what comes up after every attempt:

     

    Started CoreStorage operation

    Error: -69749: Unable to unlock the Core Storage volume

  • by nuber19,

    nuber19 nuber19 Jan 25, 2014 9:02 AM in response to wire nut
    Level 1 (0 points)
    Jan 25, 2014 9:02 AM in response to wire nut

    I Have the same problem...Have you got a solution?

     

    I actually have the password stored in KeyChain. But now it just does not work any more.

  • by Carlossos,

    Carlossos Carlossos Feb 4, 2014 11:23 AM in response to nuber19
    Level 1 (0 points)
    Feb 4, 2014 11:23 AM in response to nuber19

    Yep, same here. Do have the password stored in Keychain Access. When I put it into the field when plugging in the external hard drive, the window just shakes and refuses to do anything.

  • by henry178,

    henry178 henry178 Feb 13, 2014 11:06 AM in response to wire nut
    Level 1 (0 points)
    Feb 13, 2014 11:06 AM in response to wire nut

    I have the same issue with time machine and an external hard disk; is there any solution?

  • by clutchcity,

    clutchcity clutchcity Apr 15, 2014 5:48 AM in response to Topher Kessler
    Level 1 (0 points)
    Apr 15, 2014 5:48 AM in response to Topher Kessler

    Topher's response helped me. I had successfully used migration assistant for my new rMBP but then couldn't find the time machine backup disk afterwards. I couldn't even access it on my old computer. After following his instructions, I realize that it was because I had interrupted the decryption process after setup. The decryption process resumed after using Topher's terminal instructions. Thank you so much!

  • by Ralf M,

    Ralf M Ralf M Nov 24, 2015 8:02 AM in response to Topher Kessler
    Level 1 (15 points)
    Nov 24, 2015 8:02 AM in response to Topher Kessler

    Thanks! Topher's reply just helped me after I did a clean install of Mac OS X 10.11.1 El Capitan and my encrypted Time Machine drive didn't accept the correct password anymore through the GUI.