External HD wont sleep after 10.10.3 update

Mr. McMac said:

After updating Yosemite 10.10.2 to .3, my Seagate Expansion USB3.0 Hard Drive doesn't sleep anymore after 3 minutes of non use like it did before, although it does sleep when I put my 2014 Mac mini to sleep.
Anyone else notice this?

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I have a Toshiba External drive.
After updating to 10.10.3 I have problems with the drive shutting off.
Maybe related?

I haven't had a drive that sleeps since moving to Yosemite. That includes FireWire and Thunderbolt. Don't use USB but most have sleep in the firmware and I would think they'd be ok.

All spinners are Hitachi/HGST. All enclosures are OWC. One of those could be my issue.

Mr. McMac said:

The Seagate has it built into the firmware. If there's no activity for 3 minutes, the drive spins down and the blue LED goes out. That must mean Yosemite is sending some sort of signal to the HD to keep it awake unlike what it did in previous versions of Yosemite, and Mavericks. Again, it does spin down when I sleep my Mac. Strange, isn't it.

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Same with mine. Slept fine on all previous versions. When it comes to core functionality, nothing surprises me with Apple anymore. But I do have emoji's now.

Mr. McMac said:

After updating Yosemite 10.10.2 to .3, my Seagate Expansion USB3.0 Hard Drive doesn't sleep anymore after 3 minutes of non use like it did before, although it does sleep when I put my 2014 Mac mini to sleep.
Anyone else notice this?

Click to expand...

My problem, like yours, started when I upgraded(?) from Snow Leopard to Yosemite 10.10.3. I have 5 external drives. The two WD My book drives behave as before and stay de-spun when not being used. My two 4TB Seagates in Voyager 'toaster' holders stay spun even when my Mac Pro is asleep. My 3TB Seagate in it's own enclosure stays spun while Mac Pro is awake, but spins down when computer is asleep.

If feels like many someones at Apple have missed the first rule of software development: "If it ain't broke, don't fix it". Many things have changed between Snow Leopard (a great OS) and Yosemite for no apparent reason.

Mr. McMac said:

So it's not just me. Hopefully Apple will get their act together and fix it in the next release. In the meantime my poor Seagate is spinning away needlessly.

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Actually, I believe that hard drives constantly spinning involves less wear and tear on the drives than regularly spinning up and spinning down..

matreya said:

Actually, I believe that hard drives constantly spinning involves less wear and tear on the drives than regularly spinning up and spinning down..

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Thanks for the info. I'm really more concerned about power consumption having so many drives running constantly, particularly when the computer is sleeping.

Any possibility the disc is still being indexed after the update?