The following example shows how to create a shared secret device. The secret will be split between a slice on a local disk and a USB Pen drive.
gshsec label -v secret /dev/ad0s1 /dev/da0
From now on, when the USB Pen drive is inserted, it will be automatically detected and connected, making the secret available via the /dev/shsec/secret device.
geom(4), gbde(8), geom(8), newfs(8)