[H-GEN] autofs + losetup/cryptsetup + removable media

[ciphernaut]

Hi all,
Im trying to come up with a solution that will provide a backup scheme
on an external USB caddy.

I have had no trouble setting up the drive (I created a 10 MB dos
partition with a message not to mess with the patition layout, and the
rest of the drive as the second partition, which was then set to the
type DA - Non-FS data).

http://www.greenfly.org/tips/usb_drive.html has given me some idea how
to make it work nicely with rsnapshot, and not clash with the main sata
drives, which are also sdx.

The only problem remains is getting autofs to setup losetup or
cryptsetup upon access, and tear it down after timeout/idle. The
documentation for autofs does not give much insight into this.  The
passwords/keys can stay on the server.

Has anyone setup something like this and gotten autofs to work in this
way?  Am I better off looking at something like lufs or fuse in
combination with hotplug for a solution?

Cheers,
Marco