When would one use this?<p>When I install Fedora, it gives me the opportunity to encrypt any file system other than /boot. Since this requires you to enter the password at boot, that's good for a laptop, probably bad for a server.<p>You need root privilege to mount a loopback file system. Either (a) you've got the root password (b) the admin has given sufficient sudo privileges or (c) you use pam_mount to mount the encrypted filesystem (probably as your home directory). Am I missing other scenarios?<p>The trouble with the pam_mount scenario is that the key for the file system needs to be based on your login password. Either your account creation process involves telling the admin your password, or someone's built a collection of self service tools I'm unaware of. Changing your password also means building a new encrypted filesystem, which again involves giving the admin the new password, or invoking self service tools I'm unaware of.<p>If there are other scenarios in which to use this kind of encrypted file system, I'd appreciate hearing about them.