Originally Posted by gnashley
If you run sync before unmounting, or run eject, it should be safe to pull the plug.
that's what I'm doing now. No choice! But I have two issues with it ...
Firstly, I'm with Yan Li in wanting to follow the manufacturer's recommendations.
Secondly I prefer not to waste electrical power. Even after umount, sync, stop and eject the spindle is still spinning and the drive is warm. Warm means dissipated energy means environmental damage -- and for for no benefit
In this case the drive will be plugged into a 24x7 backup server so even a small waste adds up over a period.
EDIT: "sync" above refers to the sdparm command to flush the device's internal buffers, not the Linux sync command to flush kernel buffers to the file system.