If you are aware and paranoid on energy saving on spinning disks (which 'as they spin, they die sooner') like me, you may need :
# udisksctl power-off -b /dev/sdX
or
# hdparm -S 1 /dev/sdb
/* for hot plugs */
edit "/etc/udev/rules.d/45-sdX-power.rules" file
ACTION=="add", SUBSYSTEM=="block", KERNEL=="sdX", ATTR{queue/rotational}=="1", RUN+="/path/to/hdparm -S 1 /dev/sdX"...