File under: “What WERE they thinking?!!”
I tried that, and it appeared to shutdown the system - including a power-off. However, when I turn the thing back on, there is a warning message in the webmin page saying that power was lost and it’s doing a consistency check of the filesystem. Therefore my understanding of what happened is that the filesystem is NOT cleanly unmounted prior to powering off the system, leaving the filesystem in a potentially un-defined state. 
Ergo, I am forced to believe that someone, somewhere, made a serious balls-up of the 2.n firmware.
BTW, the WD Access software does not, repeat NOT include a “shutdown” option for this item.
I totally get what people say when they mention that a device like this is designed to be on 24/7. However, I don’t care - even gazillion-dollar-each servers rated for “six nines” uptime still have a blankety-blank-blank power switch!
Seriously folks, there will be times when you need to turn it off in a safe manner.
If I wasn’t being shipped overseas in 48 hours-or-so, I’d seriously consider wiping the device, returning it, and look for a device with the 4.n firmware in it.
This isn’t just crazy, it’s stupid. More than that, it’s carelessly stupid.
(Shaking head in wonder)
Jim “JR”
(insert picture of head with top blowing off and steam coming out of both ears)
