3 Replies Latest reply: Oct 24, 2012 5:17 PM by Alan McDonley
jpknox Level 1 Level 1 (25 points)

OS-X Lion  I now have two useless FW800 external disk drives because I cannot turn off encryption and reformat the disk.  (30 years ago, in DOS, this was called a "low level format".)

 

I think I need to use Terminal cammands diskutil eraseDisk or diskutil partitionDisk but nether of those commands work.  Apparently, I cannot format the command correctly or diskutil cannot remove an encrypted partion.  Help will be appreciated.


Mac OS X (10.7.4)
  • 1. Re: Remove Encryption - Repartition Disk
    Topher Kessler Level 6 Level 6 (9,340 points)

    You should be able to completely partition and format the disks using Disk Utility. What happens if you select the disks in that program and then try using the Erase or Partition functions in it?

  • 2. Re: Remove Encryption - Repartition Disk
    Alan McDonley Level 1 Level 1 (0 points)

    I also have this problem (although got here from Mtn Lion). 

     

    How I got to the problem:

    External 3TB disk had

      500GB unencrypted time machine backup of my snow lep partition

      500GB unencrypted time machine backup of my mountain lion partition

      750GB unencrypted data files partition

      750GB partition designated for encrypted time machine backup

       500GB unassigned space

     

    I started time machine making the backup and returned 8 hours later to find the backup 40% completed, stopped the backup, and desired to erase the partition and just live with unencrypted backups.

     

    Disk utility shows the usual "whole drive" entry with four partitions under it, but the name of the "whole drive" has changed to be the same as the encrypted partition name, and selecting the encrypted partition states I can only split the partition;  Selecting any unencrypted partition states I can only merge the partition with the one before it.

     

    I rebooted to see if that affects anything, mounted and unmounted each partition. This is looking pretty bad.

  • 3. Re: Remove Encryption - Repartition Disk
    Alan McDonley Level 1 Level 1 (0 points)

    I was able to fix my problem by:

    1) booted from recovery partition

    2) ran disk utility

    3) clicked on the encrypted partition, clicked "unlock"

    4) clicked on the encrypted partition, clicked erase tab,

        changed format to Extended Journaled (not encrypted)

         clicked erase button - Big Scare cause it briefly looked like I was erasing the whole disk.

         When it was done, the disk name went back to what it was originally - great sign.

    5) clicked on the whole disk, went to the partition tab

    6) deleted the formerly encrypted partion just to be rid of any problems

    7) added a partition in that space - extended os, journaled

    8) rebooted into my OS, all the unencrypted partitions and contents were safe.

    9) Set up Time Machine for a non-encrypted backup to the new partition and finally took a deep relief breath.