Speed Up FileVault2 Decryption

FileVault2 (FV2) provides disk encryption for OSX. I am unfamiliar with it.
I read about it at the Apple website. It doesn’t explain much. I wanted to know
how OSX handles it. To learn I tried it out.

After installing OSX I turned on FV2. The encryption was seamless. 8GB in 15m.
I installed 58GiB more of applications and copied files. Then I wanted to
re-provision the machine.

I booted into an external drive with OSX 10.9 (10.9) on it. I erased the disk on
the box. When I erased it I was asked for a new password. I provided it. I am
guessing that FV2 wanted a new password. I booted back into 10.9 and OSX
reported that FV2 is turned on. Seems like you can’t just wipe a FV2
encrypted partition. I asked OSX to decrypt the partition. It did and I tried
erasing the partition again and it worked fine. Going through the provisioning
process again I found that decrypting 58GiB takes about 2 hours.

Some experimentation left with the plan that when I want to re-provision a OSX
box I will erase the partition and re-image it and boot into it to decrypt the
partition. Surely there are command line tools to do so. I did investigate
that people I want directions that anyone may follow in the UI.

Leave a Reply

Your email address will not be published. Required fields are marked *