I'm keep digging for a solution for last few days but could not get any solution so far. I use WD Elements 2TB external USB HDD in USB 3.0 port for maximum optimization but the problem is that even after I safely remove from my file manager or Unity Dash it keeps rotating which I can feel very clearly. I'm afraid of unplugging it while spinning and I don't want to take chance.
It can not be my HDD fault as it stops spinning as soon as I safely remove from Windows OS. Also I remember that it was not the same for Ubuntu which I used prior to 14.04 LTS.
Is there any way to fix this in Ubuntu 14.04 LTS? I prefer it as simple as safely remove option. I don't prefer running any command every-time I've to remove my HDD.
sudo umount /dev/xxx
(replacing xxx with the name of your HDD, usually 'sdb')? If there are processes using the HDD this command will tell you. Paste the output here. – Eduardo Cola Jan 04 '16 at 15:24