A while back, a post on using Time Machine with FileVault encryption generated some interesting reader comments. I thought I’d follow up with some information on FileVault version 2 in OS X 10.7.
FileVault 2 improves over its predecessor in multiple ways, including inherent full-disk encryption, network recovery options, and bit encryption at the disk block level. Still, Lion users should proceed with caution and even reservation, as there are a few somewhat unexpected twists involved in using File Vault 2, and in recovering from encrypted Time Machine backups. Iljitsch van Beijnum has written a good (albeit somewhat verbose and overstated) article on Ars Technica on his experience with restoring data from FileVault 2. In short: plan your partitions carefully, especially where your recovery partitions will land, and don’t forget the recovery boot key combo (Apple + R).
Update (May 7 2012): as it turns out, if you’ve migrated to Lion and from FileVault, your encrypted volume’s password was being output to a system debug log in plain text. That’s not exactly secure.