You may wonder why this blog post is written in english but I thought this topic could be important to know for every Mac user who installed Lion shortly.
I installed Lion on my MacBook Pro right after it was released by Apple and enabled full disc encryption right after the installation of Lion. Everything worked just fine, my beloved Xcode needed a little reinstall but that was done after an hour or so. One day later I installed my new OCZ Vertex III SSD into my MacBook Pro and cloned the hard drive to the SSD using SuperDuper, it worked just fine. After a while I tried to enable full disc encryption but every time I tried to enable it the computer said: „NO“ because „some partitions types do not support the needed recovery partitions“ the suggestion was to reinstall my system on a new formatted hard drive, well thanks but no, thanks. I just cloned my 200GB system to a new one which took me 4 hours, so this wasn’t an option.
After awhile I had an idea: The Lion installer does create this recovery partition when upgrading a snow leopard installation but when I cloned my drives this recovery partition gets lost so why not try to rerun the installer? Sounds easy but you need to know a little trick to do so: If you try to just download Lion again on a Lion system the Mac App Store won’t let you do this because its already being installed on your system. You need to do a search for Lion and Option-Click in the Mac OS X Lion link in the App Store and then Option-Click on the buy-button. This will download Lion to your Mac as it did on Snow Leopard. After this you can start the installation progress once again an let it „Re-Install“ Mac OS X on your hard drive, this will keep your personal data and applications and your hard drive will get the needed recovery partition for full disc encryption. The only trade back: You need to re-install every system extension, like voices, and you need to re-run the Xcode installer for Lion to make the cli commands available again.