Setup an external sata drive as ejectable

[AlainTox714]

I use an external Sata drive for backup which one is in reality connected

to a sata port on my mobo and i want to set it as ejectable.

The reason why i would like to do this is :

When i set the rear power switch to off, everytime i use diskutil or

Disk Utility it's hangs until i set the rear power switch to on.

 

After asking to my friend Google, i din't find anything really usable.

 

Does somebody could gives me a clue or and advice for doing this?

 

Thanks in advance.