TmpUsb ZFS Passphrase
Allows automatic loading of ZFS passphrase from TmpUsb with a fallback to prompt if drive is not present.
Linux Debian Repository Installation
wget -O- http://packages.medo64.com/keys/medo64.asc \
| sudo tee /etc/apt/trusted.gpg.d/medo64.asc
echo "deb http://packages.medo64.com/deb stable main" \
| sudo tee /etc/apt/sources.list.d/medo64.list
sudo apt-get update
sudo apt-get install tmpusb-zfs-passphrase