Is it safe to remove the cable of external HDD while it is spinning?

[Miso]

I have a problem.
I insert my external HDD to my MacBook pro.
I use it and press eject (in most of the cases it does not eject because it says that something is still using HDD, so almost all the time I have to restart my mac in order to eject it).
But the HDD is still spinning even though it is not mounted. Is it safe to remove the HDD cable from my mac if the HDD is still spinning?
This problem persists with different models of external HDDs. I tried at least 3.

 

[Apple_Robert]

As long as the drive is not actively mounted and being read by the Mac, you should be ok disconnecting it.

Give the following app a try. It works well for me. One click and all my external drives are unmounted. It hasn't failed me yet. The app has been updated to being able to do this at any time and not just when you are sleeping the Mac.

Ejectify - No more "disk not ejected properly" notifications

Ejectify automatically unmounts external volumes when your Mac starts sleeping, and mounts them again after it wakes up.

ejectify.app

 

[HDFan]

If applications have open files on the disk there is a risk of file corruption if you eject it. There are a couple of tools that can help you identify the processes that keep you from ejecting the disk so you can close them.

1. What's keeping me

2. lsof command