Over the last weekend I was reinstalling my older MacBookPro (late 2011 model) again after replacing its hard drive with a fresh and modern SSD drive from Crucial 512GB. That change was really necessary given that simple file operations took about a minute, and every system tools claimed that the HDD was fine.
So after installing Mavericks I moved my home folder to another partition to make it easier later to reinstall OS X again. But as it turned out it is not that easy, especially not given that OS X doesn’t support mounting of other encrypted partitions beside the system partition during start-up yet. If you had a single user only, you will be busted after the home dir move and a reboot. That’s what I experienced. As fix under such a situation put back OS X into the “post install” state, and create a new administrator account via single-user mode. With this account you can at least sign-in again, and after unlocking the other encrypted partition you will have access to your original account again.
Having to first login via an account which data is still hosted on the system partition is not a workable solution for me. So I was continuing to find a solution which let me unlock the second encrypted partition during startup. After some search I finally found a tool which actually let me do this. It’s called Unlock and can be found on Github. To make it work it installs a LaunchDaemon which retrieves the encryption password via the System keychain, and unlocks the partition during start-up. To actually be on the safe side I compiled the code myself with Xcode and got it installed with some small modifications to the install script (I may want to contribute those modifications back into the repository for sure :).
In case you have similar needs, I hope this post will help you to avoid those hassles as I have experienced.