My Book Thunderbolt Duo 6TB does not "shut down"


since yesterday my “My Book Thunderbolt Duo 6TB” does not shut down, neither by shut down of my computer nor by “ejecting”/unmounting it from the operating system. I have to pull out the ac adapter. Due to this behaviour the “Book” gets extremely warm/hot and loud.

My system:

  • iMac 27"

  • Mac OS X 10.7.4

May someone help or provide a tip for this strange behaviour?

Thanks in advance,


 Well this type of units are designed to be on 24/7 However, it should go to Stand by after 10 or 15 minutes

Well, this is the problem. It does not go “stand by”. Even if I unmount it nor if I shut down my system.

Hello, Did you get an answer to the WD thunderbolt never going into standby? I have the same problem.



No, not until now. I will contact WD directly. As soon as I have more info I will post it in this thread.

Right after getting the ack for my “case”, there was a link: " My Book Thunderbolt Duo does not spin down after being ejected through the OS," (

Perhaps this “helps” :frowning:

I just got mine yesterday, same model running with same IMac and OS.  Haven’t come across that situation yet.  I have a related question:  Is it necessary to “dismount” or “eject” the drives when putting my iMac into “sleep” mode?  I’m sure that dismounting is necessary when shutting down (powering down) the computer, I assume.  Any help would be greatly appreciated. Thanks and best of luck with your situation.

Just got the Thunderbolt display running on my MBA and noticed the same problems.  The drives were still spinning the next morning despite the laptop having been off all night. 

two questions: 

a) how can i turn them off?  in reading the link it sounds like a known issue and there is no immediate fix.  Other than unplugging them each time i power down, anyone have any solutions?

b) is it true that these drives can be left spinning 24/7?  surely they will get hot or suffer premature wear?

thanks for the help.