3 Replies Latest reply: Aug 22, 2012 1:23 PM by ITSTORE
ITSTORE Level 1 Level 1

I have recently installed a Seagate Momentus XT 750gb hybrid drive into my new MacBook Pro. It was installed as a new drive with Lion, then upgraded to ML, and Time Machine was used to restore some files only, so not a full system restore.


I have been very impressed with the performance of the hybrid drive for things like booting because of the way it uses its 4gb SSD area, and I decided yesterday to enable FileVault to increase security. I performed Verify's in Disk Utility first then started the encyrption process which seemed fine. I even kept using the system and at one point rebooted and was presented with the FileVault logon screen at bootup displaying the enabled users as it should have, and I logged in without issue.


I left the system running overnight to complete the encryption process (which it was reporting would take 9 hours) and I had a message this morning saying that there was a problem with the encryption process and I should remove FileVault. When I go into Security & Privacy in System Preferences it immediately gives me a window titled 'There was a problem enabling FileVault' and the message 'Problems were encountered with the disk “MacBook Pro”. Please turn off FileVault, verify and (if necessary) repair the disk with Disk Utility, and try enabling FileVault again.' with a button to 'Turn Off FileVault...'. When I try to do this it asks for the local admin password then thinks about it for about 30 seconds, asks me to confirm I want to disable FileVault, then immediately gives me a new window titled 'Disabling FileVault Failed' with the message 'An error occurred while reverting the disk. (Error: -69755)' and immediately returns to the first warning of the problem again, and this just goes around in circles.


When I reboot I no longer have the FileVault logon screen and it just runs as if FileVault is not turned on, but when I'm back in ML and bring up the disk info it still claims to be encrypted. If I reboot to the recovery partition and run disk utility it will not allow me to mount the drive.


This one has thrown me. System performance is fine, all data is there, running a disk verify and permissions verify both come up clean, but obviously FileVault is not doing its job properly and I'm not sure what the problem could be. I would prefer get FileVault working properly rather than remove it. I have a Time Machine backup so I have all data backed up in case it starts to flip out, but any suggestions will be gratefully received.

MacBook Pro, OS X Mountain Lion, 13", 2.5GHz i5, 8gb, 750gb Hybrid
  • GuyGascoigne Level 1 Level 1

    All I can really say is "me too".


    I've got the exact same disk and I ran into this same problem (couldn't complete the conversion, couldn't fully disable FileVault) with Snow Leopard several months ago, and I found your message while I was looking to see if there was a fix yet.


    There are several messages around talking about similar problme when enabling Filevault - and there's a strong implication that it simply doesn't work when the disk gets beyond a certain size.  That seems crazy, but I remember that being the conclusion.  I was hoping that that might have been fixed in ML but your message doesn't really fill me with a lot of hope.


    I'll probably do a clean install at some point and see if I can enable Filevault before I restore all of my data back, but I've just not had the time to devote to it yet.


    Basically it's broken and I've not found a solution.

  • GuyGascoigne Level 1 Level 1

    BTW there's what looks like a good description of how to roll this back at




    Seems like it'll take a while but it also seems like a solid write up, I'll probably try and give it a go this weekend.

  • ITSTORE Level 1 Level 1

    Thanks for your thoughts. I'd accepted that this is not going to be 'fixed' and the drive will need wiping/repartitioning.


    The one thing with the suggested instructions is that when I do the diskutil cs list everything is listed as not encrypted. In fact I get the following....


    +-> Logical Volume Family C3F6DFBA-AE08-46A5-A678-XXXXXXXXXXX


            Encryption Status:       Unlocked

            Encryption Type:         None

            Conversion Status:       Failed

            Conversion Direction:    backward

            Has Encrypted Extents:   Yes

            Fully Secure:            No

            Passphrase Required:     No


    I'd like to think there is a way I could change this from Terminal but I'm gussing the only thing to do is back up and start again.