Just wondering if I can, using Disk Utility, format the hard drive such that it is OS X Extended (HFS+) Journaled encrypted. Will Lion be able to install on that disk?

  • Maybe you should just use FileVault and make life easier for yourself. It's exactly the same thing.
    – Slick
    Commented Sep 22, 2011 at 17:24

3 Answers 3


I'd say this is more work than it's worth since Lion clearly isn't expecting to be able to deal with the new encryption scheme. You'd be better off running Lion virtually as that's far less work to do than hacking together the parts of Mountain Lion needed for file vault 2.

The obvious catch-22 is where you need to expose that disk to Lion to get it encrypted in the first place, the recovery HD placed on that drive will allow the installer to prompt for a password and get the CoreStorage keys set up to unlock that volume for the installer.

As mentioned in the comments, it's easiest to connect your encrypted Mac to another Mac in target disk mode to get the Lion installer to run (or better to just image things) - but advanced knowledge of fdesetup and the boot process also might allow other solutions. You will likely have continual problems with automatic rebooting since Lion isn't going to know how to decrypt the boot volume nor will the Recovery Boot image want to hand off to Lion since it's not supposed to know how to handle Filevault 2 drives in the first place.

  • Is this correct? Are there any instructions for doing so? It didn't go very well for ppoen apparently. :( Commented Dec 21, 2011 at 2:47
  • @JeffBurdges Yes, I usually connect the Mac with the already encrypted volume to a second mac using target disk mode to run the subsequent OS install. That reduces the olympics needed to self-mount and potentially modify the recovery HD. I've seen that done, but it's somewhat finicky and you'll want to be a wizard running fdesetup from the command line to proceed down that route.
    – bmike
    Commented Jul 23, 2013 at 15:10

I tried to install it and it is not possible or simply not straight forward to do.

I tried it on a new MBA 2011 and a 2009 MacBook Pro. The installer will let you install lion on the newly encrypted hard drive. However it will not boot.

On the MBA air you will get the below. The Universal No Sign.

enter image description here

It was also very difficult to fix the install on the encrypted drive.

The new MBA Air only has internet recovery, somehow it cannot read the external hard drive or flash disk you installed OS X lion (from installesd.dmg). This is a big pain.

To fix the encrypted HD issue you got again use Disk Utility to reformat it in to Os X extended Journaled .. only.

If your lucky the install should go smooth. However if you get an install error, saying you need to reinstall OS X.

You need to reset the P-R ram.

Turn off the computer,
Hold down “Command”, “Option”, “P” and “R” on the keyboard,
Turn on the computer,
Keep holding down the keys until the computer restarts itself again (maybe ten or fifteen seconds at most),
Release the keys after the computer has restarted again.

All in all. I don't recommend you try to format your boot able hard drive to be encrypted. OS X has a security option that does that now. Encrypts/Decrypts files on the fly.

If someone has successfully been able to format their hard-drive to be extended journaled encrypted and be able to boot and install lion. Please let me know the instructions.

Otherwise don't do it, it is a pain to try fix once you try to format your drive to be encrypted and try to install lion on it.

  • Thank you, PPOEN, for sharing your findings. Theoretically, this can't be possible unless the hard disk has built-in support for communicating with the logic board in an uncrypted manner (such as a hidden section outside the reach of Disk Utility) before the hard disk volume kicks in. If so, the hard disk would effectively use 256 bit encryption so as to allow for FileVault encryption, which is against the U.S. export law and hence not a feasible choice for computing industry who serve customers around the globe.
    – user11842
    Commented Oct 11, 2011 at 7:06

I am guessing here:

The disk may have to be unlocked first. It will either prompt you to unlock it during the installation, or you may have to do it by accessing Disk Utility before the install process (Utility menu on the 1st or 2nd screen of the install).

Another way of doing the same thing is not to have an encrypted disk, and install Lion. After the installation completes, encrypt the disk through System Preferences -> Security. It will prompt you to restart and then it will begin encrypting the whole disk, even as you use it. Great feature.

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