Get a zone list with camcontrol:
camcontrol zone da0 -c rz -v
Get a zone list with zonectl:
zonectl -d /dev/da0 -c rz
Look at the drive zone status:
diskinfo -v /dev/da0
sysctl kern.cam.da.0
Look at EPC power modes:
camcontrol epc da0 -c list
Set the drive to spin down after an hour of idle time:
camcontrol epc da0 -c timer -T 3600 -p Standby_z -e -s
Tell the drive to go to the Standby_z power state:
camcontrol epc da4 -c goto -p Standby_z
Check the current drive state without causing it to spin up:
camcontrol epc da0 -c status -P