- Password Changes and FileVault 2
- The Guest User and FileVault 2
- Enabling Admin Users for FileVault 2 via System Preferences
- Creating an Institutional Recovery Key
- Erasing a FileVault 2?Encrypted Volume from the Command Line
- Setting a Text-Only Login Banner from the Command Line for the FileVault 2 Pre-Boot Login Screen
- Booting into Single-User Mode on a FileVault 2?Encrypted Mac
- Using Apple's Internet Recovery to Unlock or Decrypt a FileVault 2?Encrypted Boot Drive
- FileVault 2 and UUIDs
- Automating fdesetup authrestart in 10.9.x or Later
The Guest User and FileVault 2
One unusual feature of FileVault 2 is that sometimes a Guest User icon will appear at the pre-boot login screen, as shown in Figure 4.
Figure 4 A guest account appears at the FileVault 2 pre-boot login screen.
If you log in as that guest user, you don't get access to your hard drive; you can only access the Safari web browser and a network connection (see Figures 5 and 6). Exiting Safari simply returns you to the FileVault 2 pre-boot login screen.
Figure 5 The guest account restarts to Safari-only mode.
Figure 6 Guest account's Safari-only access.
To my knowledge, Apple has never commented specifically about this guest user account, but the guest user appears to be an anti-theft measure. The guest user's appearance at the pre-boot login screen is a feature tied to signing into iCloud and enabling the Find My Mac option (see Figure 7).
Figure 7 Enabling the Find My Mac option in System Preferences' iCloud preference pane.
One consequence of logging into the guest user account is that, as soon as the Mac gets a network connection, it immediately connects to Apple and report its location information, as shown in Figure 8.
Figure 8 Computer's location displayed on iCloud's Find My iPhone website.
If you don't sign in with iCloud and then enable Find My Mac from that machine, the Guest User icon won't appear on the FileVault pre-boot login screen. Mobile device management solutions that track a machine's location may also trigger the Guest User icon to appear.