I've been bouncing around several google searches and coming up empty. I have an external drive partition encrypted with Filevault2. After I enter the encryption password it unlocks properly. According to the docs, ejecting (or diskutil eject) is supposed to bring that partition back to a locked state. It does not. A simple remount is possible without the need to enter the encryption password. The encryption key is kept in memory. This is an unnecessary security risk. This encryption key has not been added to keychain. When I look at keychain, I have no encrypted drive passwords saved. I'm looking for a solution that does not require unplugging the drive, rebooting the computer or changing the encryption to a different format. Has anybody tackled this successfully? Am I overlooking something important?