I purchased the WD My Book 6TB Desktop USB 3.0 External Portable Hard Drive WDBBGB0060HBK-NESN for use with my 2015 15" MacBook Pro (top end model). I use the drive via ANKER 7-port USB3 hub, but even if the drive is directly connected to the MBP, the same problem happens. Specifically, when I sleep, the drive powers Down>Up>Down>Up>Down>Up>Down>Up>Down. (About 4 times.) This happens at every Sleep sequence.
If I use the app Jettison to avoid “ejected improperly” error dialogs on Wake, Jettison will tell me it’s safe to disconnect my drives, and during that time the drive will still be powering Up/Down, but if I yank the USB cable, the drive will power down and stay powered down.
This particular drive has no power ON/OFF switch. It is powered by AC Adapter but it uses some kind of auto sensing to detect when to power up. I can’t find details about this in the drive’s manual though, so I don’t know technical specifics of what it is supposed to do. In other words, I don’t know if it auto wakes due to it sensing power over USB or data. In any case, the drive is powering Up/Down 4 times at every Sleep cycle, and this surely cannot be good for the drive in the long haul. What should I do at this point?
(There are no other problems with the drive at all. I have 4 partitions on it, if that matters. It’s used for external storage and Time Machine backups, not booting. I am running OS X Sierra on the MBP.)