How can I decrypt a file vault 2 encrypted disk when my laptop fails to boot because of a kernel panic on startup?

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How can I decrypt a file vault 2 encrypted disk when my laptop fails to boot because of a kernel panic on startup?

here's what led up to this state- I migrated a user's data from a 10.6.8 Mac Pro to a new non-retina 15" MacBook Pro with 512GB SSD running 10.7.4 that had previously been configured with a network admin account and had FV2 turned on. The migration appeared to run successfully to completion but upon restarting the laptop it KPed. I tried to reinstall Lion from the repair partition and after authenticating with the FV2 password, it appeared to do that but once the install was complete and the system restarted, after authenticating with the same FV2 password it KPed again. I've connected the problem laptop up using FW800 to another Lion system to try wiping the drive but since its encrypted I'm unable to perform any partition or erase operations on it at all once its mounted.

Is there anything I can do other than returning it to an Apple Store?

Thanks,

Karl Cook

MacBook Pro, Mac OS X (10.7.2)

Posted on Jul 16, 2012 8:41 AM

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Answer 1

Jul 16, 2012 9:05 AM in response to Karl Cook

Try booting to the recovery hard drive using http://support.apple.com/kb/HT4718 and use the Command-R method to boot to the drive.It sounds like you've got all your data backed up, it would save you time doing an erase and install rather than fidgeting with lots of terminal commands.

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Answer 2

Karl Cook Author

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Jul 16, 2012 9:26 AM in response to thomas280

I've actually done this although I described it differently- booted with CMD+R and performed a restore of the OS. Prior to the restore, the system requested the FV2 password, I provided it and the installation proceeded to completion. However upon restart and after another FV2 authentication the laptop KPed. Which is the state we're currently in. I'm booted from the recovery partition now and trying to resolve the problem, but options seem to be quite limited as far as I've been able to determine. Do you know if there is a decrypt command I can use from terminal?

thanks,

KC

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Answer 3

Jul 16, 2012 9:40 AM in response to Karl Cook

Instead of restoring the system, erase the hard drive using disk utility in the Recovery HD and then re-install the OS, don't restore from a backup. Migrate data over after reinstalling.

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Answer 4

Karl Cook Author

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Jul 16, 2012 9:56 AM in response to thomas280

ok. I was able to use Disk Utility to erase the drive then repartition it. Then I went back to do the reinstall and I got the discouraging message: "Could not write installation finformation to disk. Contact AppleCare."

I suppose I could download the Lion installer then try to create a separate restore disk and use that to try reinstallation...

unless you are aware of any better options?

KC

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